Nuking Washington or NYC

A Merciful White Flash
Tyler Wigg Stevenson
March 31, 2008

(link at end for entire article)

Before I became a Christian, I had the worst lunch breaks in the world. They went like this:

Every day I would take my bowl of rice and beans into the noonday sun and sit on the tailgate of my '87 Ranger, which commanded a billion-dollar view. Armed with the painfully earnest idealism of a new college graduate, I had scored a job at a nonprofit organization located in a house-cum-office just off the southern foot of the Golden Gate Bridge. I'd sit there in the parking lot, humming Otis Redding, literally at the dock of the bay, watching the tide roll away. As I ate, I'd take in the bridge, the Marin headlands, Alcatraz and the East Bay, and the stunning Mediterranean sweep of the San Francisco skyline.

And every day the scenery was swept clean, in my mind's horrified eye, by the merciless white flash of a nuclear airburst.

Dust and Ashes

I was then an irreligious religion major, raised in a secular home and employed straight out of college by Alan Cranston, a four-term warhorse of the U.S. Senate who dedicated his retirement to advancing the global abolition of nuclear weapons. The crash course in nuclear policy I received my first two weeks on the job was nothing short of traumatic. My imagination had become a bit zingy from eating only rice, beans, and lettuce, and sleeping every night under my desk. (It was the height of the dot-com boom; rentals, especially for impoverished, nonprofit employees like me, were impossible to find.)

As just one example of the things that kept me awake at night: We had in 1999, and inexplicably still have today, thousands of nuclear-tipped warheads on hair-trigger alert. This is a holdover from the Cold War, when policy wonks were afraid that a preemptive nuclear attack by the Reds would destroy our ability to strike back. So we, like the Soviets, developed launch-on-warning procedures to have thousands of intercontinental ballistic missiles airborne in 15 minutes—i.e., before missiles from the other side would hit our silos. In the event of a suspected attack, we would fire back instantly, and in a half-hour, the urban centers of two continents would be burning ruins, with hundreds of millions dead.

There's not a lot of time for double-checking analysis in 15 minutes. On the multiple recorded occasions when American and Soviet early-warning radars confused a flock of arctic geese, a weather satellite, and the rising moon for a nuclear attack, it was only the sheer disbelief of each side's nuclear commanders that kept us all alive.

It's this sort of thing, along with the less apocalyptic but far more probable prospect of a terrorist bomb, that haunted me. It's this sort of thing that turns a spoonful of rice and beans to dust and ashes on the tongue.

Grim Details

Here's what was behind the white flash I saw each day from my perch on the dock of the bay:

A one-megaton nuclear explosion releases an unfathomable, unstoppable amount of energy. What happens in the time it takes you to read the next word—a millisecond— is that from that core explosion, a fireball as hot as the core of the sun envelops 19 square miles of one of the most densely populated cities in America. Instantly, more than 300,000 sons and daughters die—and maybe double that, given all the people who have commuted in to work.

In the next seconds, a blast wave roars outward from the explosion's center at the speed of sound, accompanied by radioactive heat that causes second-degree burns at a distance of 6 miles. Fifty percent of people within 2.5 to 4 miles of the explosion die then; 10 percent of those in the 4- to 6.5-mile ring. Given the circumstances, 10 percent somehow starts to sound pathetically, perversely hopeful, until you realize that's 10 percent of everyone in a ring covering more than 80 square miles, or the entire northern section of the San Francisco peninsula. The view from the heavens would look like the Devil's cigar had been stubbed out on the earth.

All in all, a minimum of 700,000 lucky souls die in the first moments, more than all the combatants killed on both sides of the American Civil War, the costliest in U.S. history. I say lucky, because nearly twice that number are desperately injured, but all the hospitals are destroyed—as are the ambulances, paramedics to drive them, and roads to drive them on. Hundreds of thousands more die from burns as firestorms spring up everywhere, and the firefighters are already dead. Many who survive being burned die of asphyxiation as all the oxygen is consumed. Radiation, a patient killer, will claim its share as well over the coming weeks and years: for decades, the death toll will be recorded in pencil, not ink. And the psychological and spiritual impact is unimaginable. We will never be over this. Never.

The entire article can be read at:

christianitytoday.com/ct/2008/april/14.54.html

Tyler Wigg Stevenson is director of the Biblical Security Covenant.

I'm not sure what sort of metric these guys use to calculate the likelihood of events like these, but it's safe to say that no one has a 20/20 crystal ball. It's all conjecture. The Clinton and Bush administrations both had more data than these geeks in Aspen, and not one of them bugged out in fear or ordered evacuations.

These predictions are little more than intuitive hunches. My hunch is that if there were to be another 'terrorist' attack it would be another city, or another kind of attack altogether. Agroterrorism. Poisoning a water supply. Blowing up major Internet backbones, nuclear plants.

The WTC, the Pentagon and the White House are major symbols, and attacking them had major symbolic as well as physical effects. My hunch is that the next attacks will be against similar symbolic targets.

In short, who knows? I say we should all move to the country and get started with CSAs.

I don't wish to belittle the question, not even in my hidden thoughts, but for the love of all the gods there ever were can we please draw a line between abstract speculation and real-world threat assessment?

Credible, accurate data on the availability of weapon-grade nuclear material, the technical ability to make a bomb that will acually explode, or the ability to steal an existing bomb, is so very likely classified beyond the ability of any "expert" to see, let alone use to support a probability assessment.

Using Occam's Razor in the absence of any personal expertise, I find it difficult to believe that a terrorist is capable of making, setting and exploding a bomb as strong as those used on Japan. We're looking at kiloton, not megaton, yields. Common sense says that local damage, radiation and fallout will be severe, but that is it. It would be no more immediate to the vast majority of Americans than Katrina on the TV was.

The rest of my answer is covered by my posts in "The enemy is us" below. No sane person, knowing of a coming catastrophe, would stick around. In my view, no sane person will give credence to a "50/50 chance in the next ten years" without demanding and getting something more than speculation based on circumstantial "evidence".

When I moved from DC to Chicago (in spring 2003), I felt safer, having recently endured the sniper, the dirty bomb arrest (Padilla turns out not to have been too serious a threat, though), the anthrax scare, and Spetember 11. We moved back to the area (NoVA) a couple years ago, and although I occasionally worry about it, I don't think about it much. The feeling of threat isn't omnipresent (although when I watched Sum of All Fears recently, it reminded me of my worries, since my wife works near the Capitol).

Overall, I don't think people can remain scared for a long time - I doubt whether a large group people can collectively remain committed to any state of mind for a substantial period of time, at least nowadays, when there are so many distractions.

Franklin, I wouldn't dismiss these experts. Joseph Ciricione broke the story of Israel's submarine-based nukes a few years ago and he knows more about nuclear proliferation than many people in the government whose job it is to know about such things.

I decided a long time ago--during the Cuban missile crisis--that if nuclear warfare were a serious possibility, I would prefer to live either at Ground Zero or beyond the fallout. Now I live in Chicago, 50 miles south of the only naval training center in the US, and surrounded by nuclear power plants. What, me worry?

Growing up in the Cold War years, I recall believing that the chance of a nuclear attack on one of our major cities was roughly 100%--or at least, that was the impression the anti-nukes, pro-Sandinista nuns in our high school liked to give.

So from that perspective a 50-50 chance seems like an improvement in the odds.

I don't think it's productive to spend lots of time speculating about the dangers of one's location. A nuclear bomb would kill more people than the Boxing Day tsunami did--but we've had the tsunami. Hurricanes, tornadoes, earthquakes, brush fires, winter storms, etc. are all varying threats depending on where you live.

A rough estimate of the daily world death rate is about 150,000, or a bit over a million people a week. Knowing that helps put death toll numbers from a projected nuclear attack into perspective. This doesn't in any way lessen the horrific nature of such an attack, or the suffering that would ensue because of it--but I still think that it's not productive to worry too much about contingencies like this.

Now, I wouldn't personally choose, at this point in my life, to live in either NYC or DC anyway, but the threat of nuclear attack is probably at the bottom of the second or third page of my reasons not to live in either place--at which point it's really just an excuse.

50-50 is the equivalent of saying "I have no idea." 50-50 is maximum uncertainty, maximum entropy. And since entropy is the opposite of 'information' (as defined by Claude Shannon), it's perfectly accurate to say these experts, with their proposed odds of 50-50, haven't given us any useful information at all.

It's interesting how New Yorkers reacted in different ways to 9/11. (As I've mentioned before, I live in NYC.) In this particular case, I felt that al-Qaeda had probably expended all its resources and that (as with the 1993 WTC bombing) it would be years before we were attacked again. So during the remainder of 2001 and for the next few years I felt no apprehension at all. (For that same reason, I give no credit whatsoever to the Bush Administration for there not having been any more attacks.)

By the same token, though, as time passes I'm becoming more worried.

The only way to respond is that it is paranoid nonsense. The odds of a nuclear attack on NYC (as fervently as one may wish for one) or DC (with even more fervent wishing at times) is probably 0 to none.

Between 1960 and 1985 I bet these experts put the chances of American cities getting nuked by the Soviets at 120%.

In my profession there's a a lot of visualization fallacy and a good amount of probability fallacy and statistical fallacy. So this particular line of plausibility argument(s) provokes me to utter skepticism, given the lack of evidence for it. The only serious argument for paranoid expectations or lack thereof is one that actually understands the opponent. That properly understands the history and the politics/hostility that is his motivation.

What I see generally in American culture, ignorant and in denial about Al Qaeda's motivations as it is, are two older paranoias projected onto it. Al Qaeda is objectively puny enough, and sufficiently unknown/alien, and came at the politically "right" moment, that it serves as scapegoat for far more than its particular deeds.

In the cities there is/was lots of Cold War nuclear annihilation paranoia that was bottled up, begun by the Cuba missile crisis of 1961 and added to until the late 1980s. That got carried around until it was safe to release it. (The Soviet disarming of the mid/late 1990s made it safe to do so.) The dominant one in rural areas is fear of The Other, the White Settler paranoia of the Indian and Indian raids.

So American city dwellers spent a couple of years reveling in paranoid visualizations of nuclear destruction. Americans of more rural background went on paranoid and religionist/racist streaks against Arab-Americans. And also, perhaps more so, Latinos- who are the major manifestation of American Indians. Who the children of the Settlers realize are quietly and peacefully undoing much of the Settlement.

Once you break down the conflations, Al Qaeda is hardly the foe it is pretended to be. Even close to half of the death toll on 9/11 was a function of bad luck and bad equipment rather than the attacks themselves.

What bothers me about paranoia is that it entails an abdication of responsibility. The paranoiac invariably makes him/herself part of the problem rather than part of the solution.

Regarding terrorist nukes:

1. The key barrier to entry for the nuclear club (for both state & non-state entities alike) is the availability of fissile material, _not_ technical expertise. See the "Nth Country Experiment", wherein three newly-minted physicists, at LLNL's behest, were able draft with a workable bomb design using only unclassified, public-domain materials. In the 1960s, without PCs or the Internet. As to the probability of AQ acquiring sufficient fissile material for a nuke...I plead insufficient data.

2. A terrorist's "improvised nuclear device" would probably end up being fairly low yield - at most tens of kT (and more likely less), not the megaton-range weapon of the 12:30 post (*). It would probably also be heavy (i.e., hundreds of kg), not suitcase-size. More sophisticated stuff (i.e., higher yield, lower weight) requires testing as well as simulation, which in turn requires lots of fissile material; this is the sort of stuff that's classified - and a good thing, too.

3. Nukes have limits (just like any other weapon). A 10 kt weapon would devastate a circle 3-4 km in diameter, producing first-degree burns 1 km beyond that (**). Prompt radiation actually wouldn't be a concern; anyone receiving a fatal dose would probably already be dead from collapsed buildings or burns (***). Fallout would be, but even that has a limited range. (****)

[Note: This isn't my area of expertise. Corrections welcome.]

(*) See Nuclear Weapons FAQ, Sec. 4.2.6.

(**) See Nuclear Weapons FAQ, Sec. 5.6.1.1 & 5.6.2.

(***) See Glasstone & Dolan, "Effects of Nuclear Weapons", Figs. 8.33a & 8.64a, Table 8.37, & Sec. 8.65. Correcting for a surface burst, the max range for 300 rad gamma & neutron radiation would be ~2 km & 1 km, respectively.

(****) See Table 3 in Bell, W.C. and Dallas, C.E. "Vulnerability of populations and the urban health care systems to nuclear weapon attack". International Journal of Health Geographics 6:5 pp1-33 (2007). Available here:

pubmedcentral.nih.gov/articlerender.fcgi?artid=1828719

Also here: dmphp.org/cgi/content/short/1/2/80

Regarding Israel's wars:

Six-Day War: 779 KIA, 2,563 WIA
War of Atonement: 2,656 KIA, 7,250 WIA (*)

The UN put Israel's 1970 population at ~3 million. Compare with a 2001 US population of ~300 million. Further comparisons left as an exercise to the reader.

(*) Numbers for both wars taken from Wikipedia (I was lazy). Doubters are welcome to verify elsewhere.

Yeah, better get FAR away from NYC and DC. If I were you, I'd move someplace safe, like Oklahoma City.

Okay, bad example...

Rod,

My God, man, your blog has turned into the gloom-and-doom, Apocalypse Now. Almost every post is about the end of the U.S., the end of the climate, the end of the world, the end of Anglicanism, the end of oil...

I used to come here because the discussion on politics was profound. Now I come here and have to leave really quickly to get a Xanax! My 9/11-PTSD flares!

Less catastrophe, more politics, please! It's easier on the stomach.

There's Larry Craig and David Vitter sponsoring the latest Protect Marriage Amendment as an example.

I'm not joking.

It's depressing here, not inspriring. And scary...

Maybe it's depressing because no one can read it with the dark blue background. More seriously, does no one else have trouble reading this? What have you done to correct this?

Rod -

Perhaps a nuclear explosion in NYC or DC will accelerate the onset of the Rapture! Won't that be awesome?

I agree with Charles Cosimano - the chances of a nuclear attack are vanishingly small.

If however it did occur, I would not want to be a resident of Mecca or Medina the day after. We will survive. They won't.

And those that do will be calling Western prayer lines on their decadent Western cell phones asking about Isa Masih.

As Renan perspicaciously phrased it, " Affranchir le musulman de sa religion est le plus grand service qu’on puisse lui rendre. (To free the moslem from his religion is the greatest service that one may render him).

My business brings me into Manhattan (from Brooklyn) several times a week. Every time,without fail, I drive out of the Battery Tunnel and past Ground Zero. There, my best firend in 6th grade, a friend I was hanging with but 2 days prior and numerous neighbors and acquaintances died horrible deaths. The thought that it could happen again is a given, not even a fear any more. My wife, brother, uncle and more people than I can count work in Manhattan. Even fun things-driving to a Yankee game or a Jet game or a Ranger game or a concert or a trip to visit a friend or relative now have that unstated given sense of horrible possibility. But you ahve to go on living. That fear was there in the days following 9/11 when everyone was convinced that there was a bomb ready to blow us all up planted somewhere in the City. I know NYPD and the FBI were. Whether that was an Al Qeada dry run or paranoia, who really knows?

If we moved, what kind of life we would lead afterward? Would it be living at all? I'm staying. At least until we can get a house closer to the beach.

Roland is on to something, though.We grew up facing Soviet mutually-assured destruction. The Soviets, what ever else, were rational. So rational, in fact, a whole bunch of'em have moved right here to Brooklyn(and throughout the tristate area).It's not uncommon to see 2 white people talking and for a moment not to recognize that they're speaking Russian. When people seriously suggest the Russians or Chinese would ever attack us, I have to laugh. They're going to bomb their money and their brothers and sisters?

Islam, however, is not rational. The next time, I suspect the PC nonsense will be done with forever. And sadly it may take that to open our eyes to the savagery and evil of the worshippers of the blasphemous Arab rock god and his pedophile murderous thieving prophet. It's hard, but it's true and we all know it; the more we read about Islam and the Koran, the more we know the 9/11 hijackers and the 1993 WTC bombers were carrying out their sick religion, not debasing it.

The kabbah-that rock their march around in Mecca-was worhsipped by Arabs prior to Mohammed. Mo just appropriated it, as he did with parts of Judaism and Christianity.

Bugg: The kabbah-that rock their march around in Mecca-was worhsipped by Arabs prior to Mohammed. Mo just appropriated it, as he did with parts of Judaism and Christianity.

This is correct. And increasingly Western scholars will deconstruct the Coran as they have the Bible. Christoph Luxenberg (a pseudonym, necessitated to protect him from the rational discourse of the Peaceful Religionists) has pointed out the probable Aramaic origin of many incomprehensible and grammatically incorrect portions of the Coran. Certainly one would expect that Gabriel would have dictated the "Word of God" flawlessly to Mo. Whether the illiterate Mo repeated it flawlessly, and those who transcribed onto potsherds, bones, and discarded soiled garments, did so flawlessly is another question.

But how much more reasonable to assume the the distortions of Judaism and Christianity that pervade the Coran are the result of an ignorant peddler overhearing and misunderstanding other merchants in the souk speaking a different Semitic language? Hence seventy two raisins are transmogified into a like number of virgins. Hell, Mo couldn't even keep the Biblical Mary's straight.

MI
2. A terrorist's "improvised nuclear device" would probably end up being fairly low yield - at most tens of kT (and more likely less), not the megaton-range weapon of the 12:30 post (*). It would probably also be heavy (i.e., hundreds of kg), not suitcase-size. More sophisticated stuff (i.e., higher yield, lower weight) requires testing as well as simulation, which in turn requires lots of fissile material; this is the sort of stuff that's classified - and a good thing, too.

Exactly. We are, in this crazy paranoid fantasy where terrorists are trying to nuke the US, talking about an incredibly low-yield explosion. Possibly less powerful than the Oklahoma bombing.

Nuclear blasts require two or more pieces of subcritical nuclear material slammed together, using a conventional explosion. How powerful the explosion is depends on several things, but mainly how well (and thus how long) it is forced together, because it attempts to fly apart almost immediately. This is why an accidental nuclear explosion couldn't take out even a building.

So, ironically, the problem with nuclear bombs isn't the explosive material per se, nor the knowledge to make it explode. The problem is the incredibly specific explosives and the 'interlocking' classified timed patterns that our military uses to build actually useful bombs. Otherwise you'll end up with a 'nuke' that's slightly less powerful than the conventional explosives you used to build the nuke, which hardly seems the effort. Anyone with weapons-grade uranium can make it explode if they pack enough explosives around two slabs of it.

When we talk about North Korea and Pakistan having 'nukes', those are the types of nukes we're talking about. A truck-sized weapon that would probably do the same amount of damage as a fuel-air bomb. (And, remember, our sole protection against fertilizer fuel-air bombs is that it's tagged so we can trace it, which is hardly helpful with suicide bombers.)

MI and DavidTC.

It is my understanding that gun type weapons only work for Uranium bombs and spherical implosion is required for Plutonium bombs. Also one non-fissionable Plutonium isotopes is really hard to separate from the desired fissionable isotope as they differ in atomic weight by only a single neutron. So Plutonium bombs are really hard to build.

This is why Iran is working on a Uranium bomb and North Korea's bomb test didn't work out so well.

[Apologies in advance for the long post.]

gun type weapons only work for Uranium bombs

Concur in part. Pure Pu-239 could also be used in a gun-based design (*); it's the other Pu isotopes that screw things up.

spherical implosion is required for Plutonium bombs

I fear I must disagree. From NWFAQ Sec. 4.2.6.2:

[A] spherical implosion system does not seem to be required for reasonably fast insertion at low levels of compression. [...] Developing linear and cylindrical implosion systems fast enough to produce a highly destructive terrorist bomb appears to be feasible. The flying plate line-charge approach is sufficiently simple, and testable, that a low resource group could develop a workable system. Even plane or cylindrical explosive lenses are not out of the question, although they are probably more difficult. [...] A design might use the cylindrical collapse of a hollow ring of plutonium metal (as the delta or alpha phase), or cylindrical compression of a solid delta-phase aluminum-plutonium alloy disk. No more than about 10 kg of plutonium would be required in such a design, if a reasonably good reflector were used. Such a weapon might weigh as little as 200 kg.

See also here: nuclearweaponarchive.org/News/DoSuitcaseNukesExist.html

If you have sources to the contrary, _please_ let me know. I _want_ to be wrong about this. The idea of terrorist nukes (of any yield) is more than a little discomfiting.

one non-fissionable Plutonium isotopes is really hard to separate from the desired fissionable isotope as they differ in atomic weight by only a single neutron.

Disagree. Yes, the 1 amu difference between Pu-239 & -240 (or -238 on the other) complicates matters vis-a-vis uranium, as does toxicity, neutron emission, & self-heating. OTOH, the inherently high Pu-239 content of reactor-grade plutonium - in the tens of percent at least, and more likely 50-80% - would reduce the required enrichment capacity by orders of magnitude as compared with natural uranium (whose U-235 content is ~0.7%). A given enrichment facility - whether using EMS, gas diffusion, centrifuges, or AVLIS - could produce far more bombs using reactor-grade plutonium than natural uranium (**).

Note that the problem posed by Pu-240 isn't that it's non-fissile, but rather that its high rate of spontaneous neutron emission increases the probability of predetonation (and hence inefficient energy release). AFAIK, Pu-238, -239, -240, -241, & -242 are all fissionable.

Plutonium bombs are really hard to build.

I agree, in the abstract. Given a choice, a low-tech actor should prefer HEU to Pu owing to the relative simplicity of gun designs. OTOH, note that India, Pakistan, & Israel have all built Pu-based weapons (along with the other nuclear weapons states), which implies that the difficulties associated with plutonium are not insurmountable even for nations of limited means.

(*) NWFAQ, Sec. 6.2.2.5.

(**) NWFAQ, Sec. 6.2.2.10.

Based on what I've read (mainly NWFAQ, but also elsewhere), it seems that, given fissile material, terrorists with engineering & physics expertise could design & build at least a low-yield nuke, with a yield in the 1-10 kt range. Note that even a 1 kt weapon would be 250x more powerful than OK City (2 ton yield, IIRC). Even a 100 ton weapon (pathetic, from a nuclear standpoint) would be substantially more powerful than an FAE (which has a 10-ton yield, IIRC).

The Russians demonstrated a FAE which had a 44-ton yield recently, but no one's going to build one of those.

There's a fundamental problem with nuclear devices. You need to test them, or they will simply sputter. It is incredibly easy to build a device that can start a nuclear explosion if you have the materials. But it's going to be a 'nuclear meltdown throwing chucks of uranium across the room' lame explosion.

No, you have to build a device, and test the explosives under laboratory conditions, and run computer simulations, and explode a few bombs, and then you'll get something that works.

Like you said, North Korea's test was in the hundreds of tons, and that are after years of government funded research. That's the probably better than the bombs we'd get from terrorists.

And even then, assuming they do it, it is very difficult to build a nuclear device that is actually cheaper, per explosive yield, than just buying diesel and fertilizer and building a dozen truck bombs and scattering them around a city.

And, as a bonus, 3/4th of the explosion doesn't get wasted on empty air. There's a reason we don't set off nukes on the ground when we bomb places, cause the blast just reflects upward. Terrorists might manage to get a nuke ten or twenty stories up, but that's still way below optimal height. With lots of small explosives, they can be placed under buildings and bridges and whatnot.

If terrorists can afford the hundreds of millions of dollars that nuke development and manufacture costs, I seriously hope they spend that money on that stupidity and take out a square mile of a single city, instead of simply buying tens of thousands of used cars, filling them with explosives, and blowing our interstate system to kingdom come so tens or hundreds of millions starve to death.

Seriously, this reminds me of a sci-fi movie where aliens try to destroy the earth and we fight them off. Ignoring the fact that the aliens have powerful stardrives on their ships that they could attach to any moderately-large asteroid and send it crashing into the earth at .9C or faster, splitting the planet in half.

If terrorists have the resources and money to build a useful nuclear weapon, they have the resources and money to destroy or at least seriously cripple the US in a thousand other ways. They might buy or steal an existing nuke, but that's an entirely different set of problems.

Dreher needs a brain. Goldberg needs...I dunno...something resembling a brain. Who pays these people to write? And, why?

There's a fundamental problem with nuclear devices. You need to test them, or they will simply sputter.

For more sophisticated designs (e.g., fusion boosting, thermonuclear), this is true. But for a simple one-stage fission device, conservative design practice & computer simulation could probably eliminate the need for testing. You just build conservatively, with redundancies, and with less efficiency than would otherwise be the case. You end up wasting lots of fissile material, and a bomb that's much lower-yield & heavier than the best in the US arsenal. But you still get a 1-10 kt yield (*).

There's a reason we don't set off nukes on the ground when we bomb places, cause the blast just reflects upward.

It's true that an airburst produces more efficient blast effects than a surface burst. E.g., the range for 4 psi overpressure for a 1 kt groundburst is ~1700 ft, vs. 2600 ft for ideal airburst height (**). (For a 10 kt burst, double that.)

[BTW, the calcs in my 0:00 post were off; I accidentally used airburst formulae. Corrected version: "A 10 kt weapon would devastate a circle 2 km in diameter (***), producing first-degree burns over about the same area (****)"]

As for the economics of nukes...I suspect you're probably right. I would point out that the bulk of nuke production cost is in developing/building facilities for enrichment or reprocessing; given sufficient fissile material (e.g., via theft), my SWAG is that terrorists could build a nuke for far less than "hundreds of millions of dollars".

(*) NWFAQ, Sec. 4.2.6. Money quote:

Since every nation to develop nuclear weapons appears to have succeeded on their very first weapons test (with the possible exception of India, the information here is conflicting), and other nations have deemed it unnecessary to even test their arsenal in advance (the US with Little Boy; South Africa and Pakistan), there is legitimate grounds for doubting how essential full yield testing really is. The US did not experience its first test failure until 1951 with its 18th test. It is clear that weapons can be built without full yield testing (or even hydronuclear testing), but considerable information can be obtained with sub-yield testing - especially for nations without prior test experience. In the absence of testing a nation will be forced to make use of more conservative, and less highly optimized designs, and will have a higher level of uncertainty about actual weapon performance. Certain design options (perhaps fusion boosting, as an example) may also be infeasible.

(**) Glasstone & Dolan, "Effects of Nuclear Weapons", Fig. 3.73c.

(***) "Effects of Nuclear Weapons", Fig. 3.73c & pp. 115-116 (1977 ed.). By "total devastation", I'm assuming an overpressure of 5 psi.

(****) "Effects of Nuclear Weapons", Eq. 7.96.3. Values for f & t taken from Sec. 7.101 & Fig. 7.98, respectively. Q = 2.5 cal/cm2, corresponding to first degree burns on a light-skinned person from 10 kt yield; see Fig. 12.64.

DavidTC, you've made a good case and convinced me.

DavidTC - I suspect we'll just have to agree to disagree WRT the feasibility of terrorist nukes.

Fair enough. I just think the difference between theory and practice in building a nuke is larger in practice than it is in theory. ;)

FWIW, as I mentioned before to MH, I sincerely hope I'm wrong, and that I'm underestimating the difficulty associated with building such weapons. It would help me sleep easier at night.

I, paradoxically, sleep much easier at night because terrorist attacks are so easy. Not nukes, but other attacks. Some of them would cause widespread panic and are incredibly cheap and almost unstoppable, like the organized teams of 'DC-snipers'. Each two person team literally needs a car that can be modified in an hour, and a rifle, and let loose to roam the countryside.

The fact that no one's bother to do them demonstrates one of two things: Either we've actually managed to very seriously cripple terrorist networks, or they do not wish to attack us. I believe the second is true.

Fear-monger much?

Red alert!