How much warning of nuclear attack?

Been reading an alternate timeline on if missiles had been launched during the Cuban missile crisis, and that made be wonder - how much warning time would the US or France or the UK have if Russia or China launched nuclear missiles today (or vice versa)? How long until impact? How would the public of each of these places be notified?

I’m just sort of curious on the timeline nowadays. I know the US has bunkers and continuity of government and so on, but how much advance warning do they need to put those plans into action? I seem to recall reading “20 hours” somewhere, but I think that was in one of the alternate history timelines (can’t recall if 60s or 80s or some other timeframe) and I definitely don’t recall the author’s source of info, if it was even given.

Of course, then there’s fallout and HEMPs (not really sure how much damage from that) and the possibility of nuclear winter (could not find scientific consensus on severity and such). But I’m really interested in the lead up, rather than aftermath, with these questions.

During the Cold War, the four minute warning was the number that used to get thrown around a lot. That was supposedly the time from when the military confirmed that a launch had happened until the missiles hit their target.

Since we don’t do “duck and cover” drills in school anymore, I think that most people would just end up confused by the sound of air raid sirens. There’s the emergency broadcast system, but a lot of folks aren’t tuned in to radio and TV these days as they are logged into the internet instead. I suspect that those four minutes will have come and gone before most folks realize that an attack is coming.

And even then, what exactly are you going to do if you find out your city will be nuked in a few minutes? That’s not enough time to do much except to scurry into the basement, bend over, and kiss your backside goodbye (and pray that you aren’t anywhere near a direct hit).

ETA: Actually, the emergency broadcast system was retired in 1997. It’s now called the Emergency Alert System. There is also a system in place to also send alerts to smartphones, which began operation in 2013.

A land-launched ICBM’s flight time is about 30 minutes from launch to impact. Modern spy satellites would detect any such launch almost instantly.

If a nuclear launch were detected, the President would immediately be hustled to Air Force One and would direct operations from there. On 9-11 the President was airborne about 70 minutes after the first tower was hit. However, there was a lot of confusion about the nature of the attack and whether or not the President himself was in immediate danger. If NORAD had spotted the launch of ICBMs he probably would have been in the air within 20-25 minutes. Cheney was evacuated to a secure bunker less than an hour after the first tower was hit.

I always assumed we’d know the Soviet’s missiles were in-bound when we saw our own missiles out-bound.

Thanks for the information.

And engineer_comp_geek, I have heard of the four minute warning as part of “Protect and Survive”. Don’t know why I didn’t think to look up. Thanks for reminding me of it. I did attribute the shorter time to the UK being closer to the USSR, but was unsure how much technology would change that.

Great - thanks for the info. I found a reference to 20 hours to evacuate congress to a bunker in a test in 1984, but haven’t found the source yet. Obviously, that would have to be in a situation with a lot buildup rather than a surprise launch.

The four minute warning on the U.S. side assumes that the launch would come from a sub. That gives you significantly less warning than a land-launched missile. I’ve always heard 20 minutes for a land launch but I don’t have a cite for it. For all I know that number may have come from the movie The Day After.

I have a vague recollection of Jimmy Carter actually testing how quickly they could evacuate after getting briefed on it by his military folks shortly after taking office. As I recall, they didn’t hit the numbers that were advertised to Carter.

I know subs have a shorter time. And we wouldn’t have any warning for a terrorist with a suitcase bomb (though at least that wouldn’t be like big bombs all across the country). But land-based missile launches are really the numbers I was looking for at the moment.

I remember seeing a book on my teacher’s desk in the mid-80s with the title “WWIII will last 20 minutes” or something like that.

The four minute warning was a UK thing- being so much closer to the USSR, the warning time would be that much more compressed.

For the continental US, the general time for ICBMs was on the order of half an hour between launch and impact.

SLBMs would indeed have a shorter time, but it’s expected that in an all-out nuclear war, they’d primarily be targeting bomber bases and ICBMs, not cities, under the theory that if the SLBMs and ICBMs were launched simultaneously, the bombers wouldn’t have time to get airborne before the SLBMs hit, and maybe they could hit some ICBM silos before they launched as well.

As The Hampster King correctly notes, flight time for a ballistic missile launched from Russia to the continental United States (CONUS) is approximately 30 minutes. Although it would be possible for a ballistic missile submarine (‘boomer’ in Navy parlance) to approach closer and fire an SLBM on a supressed trajectory with a shorter flight time a la the hypothetical attack profile suggested in The Hunt For Red October in reality Soviet nuclear submarines (and to the extent that they still operate, those from the Russian Federation) typically patrol in the Barrents Sea and fire over the Arctic, so the flight time is not much less than an ICBM-based launch.

Also, one of the primary functions of SLBMs is to provde ‘second strike’ capability; that is, to be able to assess an opponent’s remaining strategic assets and warmaking capability after an initial exchange and target those areas specficially. Up to the late 'Seventies, US SLBMs lacked sufficient accuracy to target specific installations and were intended to be targetted at ‘soft’ targets (e.g. population centers and manufacturing/agricultural zones) as a deterrent against further attack. Accuracy of Soviet weapons, while not as bad as often suggested, lagged US capability and likely also targetted ‘soft’ targets.

Launches against the US and allies are detected by Defense Support Program Satellites (DSPS) which orbit the globe looking for infrared signatures which are characteristic of large ballistic missile plumes and nuclear explosions, both of which are quite distinct from other natural or man-made phenomena. The DSP satellites and the discrimination software behind it should be able to identify a launch almost instaneously, and it would only remain for NORAD personnel to confirm that the launch is valid (e.g. that the trajectory of the plume is following a ballistic path that would overfly the United States or allies) to issue a launch warning at the executive level.

How fast that would actually be converted into public notice is unknown and essentially untested, especially in the post-NATO/Warsaw Pact era. The policy during the Cold War was “Launch On Warning”; that is, with clear signs of an attack the default policy was for the National Command Authority (NCA, e.g. the President or his successors if he is out of contact or incapacitated) to issue launch orders against a set of plan options, which offers the opportunity for a war borne out of error or misinterpretation. The current response plan (OPLAN)–the details of which are classified–is supposed to specify more selective options, but that just means more decisions to be made. It seems likely that it would take at least ten or fifteen minutes before confirmation of attack and launch orders–which would likely include public notification–to be issued.

Note this assumes a strategic mass attack using large ballistic missiles (whether land- or sea-based). This is the ‘doomday scenario’ that US deterrence efforts were designed to counter but do not encompass many other potential modes of nuclear attack, including fractional orbital bombardment (FOBS, a delivery vehicle launched into a non-ballistic orbit so that it looks like a satellite, and approaching from an unexpected vector), high altitude electromagnetic pulse (HEMP, intended for wide scale disrutption fo communications and industry), delivery via low altitude, low observable bombers or cruise missiles, and of course smuggling a nuclear weapon via container ship or other means; all of these scenarios, while not the same class of strategic threat, would offer little or no warning, and it may not be possible to determine the source for a retaliatory response.

‘Nuclear winter’ (if it is as significant a phenomena as suggested) and radioactive fallout are secondary effects that would occur after an attack, and little can be done about them other than to shelter against them and stockpile resources. Against the attack itself, the only real defense is to be well away from the affected zone where heat and blast effects will destroy unreinforced structures and unprotected people. The initial radioactivy from normal weapons is negligable because over distances shorter than the blast effects the air is opaque to X-rays and other ionizing radiation. However, ‘enhanced radiation devices’ (i.e. the neutron bomb) which are designed to maximum fast neutron yield over blast effects can activate normally inert materials through fast fission and create highly radioactive effects outside the blast zone. Realistically, if you are anywhere near a target area, there is little that could be done in the short period of potential warning that will materially impact your long-term survival.


Sub-based missiles have always been a fear for a decapitation strike, one of the more unpleasant scenarios. Their very short flight time makes that a scary possibility.

I’m not able to post the link right now (sending this from a friend’s IPad, don’t know how to do it w/o a mouse), but the Wikipedia page for the Norwegian Rocket Incident includes a pretty informative (and scary) account from Boris Yeltsin’s point of view when a rocket launched by Norwegian scientists initially mimicked the trajectory of a nuclear missile fired from a Trident in the Barents Sea. IIRC, his advisors were able to determine that the rocket was harmless eight minutes into the ten minute window that he had to order a retaliatory strike.

That incident ( is also why doctrine has always distinguished between “We think the enemy has launched a whole crapload of stuff at us” vs. “We think the enemy has launched one missile at us.”

Almost none of the consequences of a single incoming missile can be mitigated by an immediate counter-attack. Far smarter (and stabler) to prepare now to counter-attack but hold fire until after you’ve got positive confirmation of what did happen, not what seems to be happening.

This is also why redundant hardened command and control systems are stabilizing. It avoids the rush to shoot in a panic.

The “four minute warning” is absolutely originally culturally a product of British civil defence stuff in the Seventies and Eighties.

Surely a garbled version of the old story of Zbigniew Brzezinski testing the White House evacuation procedure by just announcing an attack and seeing what happened. The usual version is that chaos reigned and Carter would have died if it’d been real.

An old thread on the subject.

IIRC, during Carter’s tenure, they did another study about people ‘evacuating’ the cities in the event of incoming nukes. It seems to me that they postulated that NYC would take from 3 days to a couple of weeks. I think that that sort of marginalized the EBC, but, people felt more comfortable with it.
Art Buchwald wrote a hilarious essay about it.

My boomer SSBN 608 was the first boat to fire a live Polaris missile down range with a nuclear warhead on it in the early 60’s. I reported aboard in 1967 and in 1968 out of the yards at Newport News we fired seven missiles in row one minute apart from the Canary Islands towards a missile firing range off PR 2,500 miles with all seven practice warheads coming within 50 yards of the target.

You have a lot of time to talk to each other in Sonar with this same subject coming up. “How long would it take from first launch to find us and wipe us out”

about 15 minutes.

Putin himself would have to give the order for any sneak attack (no Red Octobers for us) and the preparations would give them away. Like todays terrorist the air waves would be a tell tell sign. Not that helps us …

The subs don’t go that fast to remain stealthy and when they do they give off certain cavitation noises of a nuclear submarine in a hurry. Not all Russia submarines are lucky enough to have a USN SSN fast attack on their baffles to stop such an attack, but we would be looking for them as Putin puts plan B into effect telling President Obama to stand down or he will finish the job and have the other half of the submarine launched missiles unleashed.

Not sure what President Obama would say, but I would say, “Hell no”

How much time would the country have? As in us the citizens? As in “how long it takes for the military people to analyse and verify an attack and then inform the president?” Or “how long until alarm bells start going off in various military observation posts?”

We the citizens will never know until the mushroom clouds appear.

In the case of a nuclear attack, isn’t there the danger that an electromagnetic impulse from the nuke would disable the Presidents plane? Or is that Planet X conspiracy theory type of shit.

The aircraft is specifically designed to withstand EMP effects, IIRC.

I’d be interested in information on EMP/HEMP. I’ve read a little, but read contradicting things, and I don’t know enough to know what’s accurate.

As I understand it, it’s only a high-altitude EMP (HEMP) that even has the potential to knock out half the US in one blow? Regular air-burst and particularly surface burst bombs would not have the range (EMP is line-of-sight and would be blocked?). And, stronger bomb = stronger EMP. But I’ve heard everything from “it’ll melt your electronics” to “if you’re outside the main blast (where buildings fall on you), you’ll probably be able to drive your car, even if some systems are damaged.” And it’s my understanding that having no power in the device (it’s turned off or not plugged in) affords some protection, but I’m unsure how much. And I’ve also heard, but do not know if is accurate, that the higher the altitude, the weaker the EMP actually is (because it’s spread out further/less concentrated).

But really, I don’t feel like I have a good grasp on the matter and would like to know more. Read the Wikipedia article, but it didn’t give me the kind of information I was looking for in layman’s terms.