Nuclear deterrence has kept the peace for eight decades by combining capability with clear, credible communication. Cold War strategists understood that nuclear deterrence depends on clarity, so adversaries know exactly where the red lines are. In the space of a few weeks over the Gulf crisis, the Trump administration has replaced that clarity with a fog of contradictory signals and hastily-improvised deals, with consequences that may outlast the ceasefire.
Thankfully, President Donald Trump did not unleash nuclear weapons onto Iran on Tuesday 7 April 2026 and, in the words of some in the UK, one can once again buy a bunch of green bananas with some confidence. Trump held back, albeit after much bombastic and troublesome rhetoric that had even some of the firebrands of the MAGA movement mentioning the 25th Amendment, the US constitutional mechanism for removal of a president for incapacity. In the 7 April instance, unspecified doom was avoided by means of a ceasefire.
Nearly a week later, the ceasefire appears to have partially unravelled in several different ways – with Iran having launched strikes across Bahrain, Kuwait, Qatar, Saudi Arabia, and the UAE; initial diplomatic talks to resolve the conflict being unsuccessful; and Trump ordering a US blockade in the Strait of Hormuz, with the intent being to prevent Iran from selling oil, and so coerce them into agreeing a deal more favourable to US interests. Despite these developments, thus far, open hostilities between the US and Iran have not yet restarted.
Regardless of the granular detail of events in the Gulf, the pendulum-like swings into and out of catastrophic threats have, in fact, eroded America’s nuclear deterrent. While President Trump’s nuclear threats have been veiled or implied, they have been veiled without much subtlety. Threats to end a civilisation can be taken to mean nuclear destruction.
Since the late-1940s, the USA has relied upon nuclear weapons as a strategic deterrent. For decades it also relied on nuclear weapons as a possible force multiplier for conventional warfare, although this tactical nuclear mission mostly went away with the Army and Navy getting rid of their tactical nuclear weapons in the early 1990s.
For strategic deterrence to work, however, several things are needed. Some of these are, for lack of a better phrase, physical components of deterrence. There need to be nuclear warheads that will function, the ‘stockpile stewardship’ which ensures that there is no doubt that the weapons will work as intended. There needs to be enough weapons and delivery systems, with crews and support, to ensure that, if needed, nuclear weapons can be used where needed. None of this is seriously in question in the USA and billions are spent keeping it so.
There are less-physical components of deterrence. One of these is continuity. Authority to use nuclear weapons is vested only in the President. This is why there are twelve uniformed military officers, six for the President and six for the Vice President (VP), who take it in turns to accompany the President and everywhere he goes, with a heavy briefcase (known in the trade as ‘the satchel’, not ‘the football’), is to provide a visible sign of the ability of the President to communicate with the strategic nuclear deterrent. The reason why a similar watch is held on the VP is to ensure that some sort of accident, assassination, or attack does not decapitate the nuclear deterrent. As the Soviet threat evolved from bombers to missiles, thus reducing time to act, military aides were assigned part-time to the VP, going full time in 2001, as a safeguard.
The military aides should be considered the publicly-visible tip of a largely invisible iceberg. Numerous other measures are in place to ensure continuity, such as reliable and survivable communications to prevent a virtual decapitation. Indeed, a bit of an ‘electromagnetic pulse panic’ in the 1980s and 1990s drove a lot of investment in strategic communications.
Another component is credibility, and it is best described as a two-sided coin. One side of the coin is clarity and the other side is ambiguity. Clarity is needed in nuclear deterrence. So-called ‘red lines’ were clearly articulated in the height of the cold war. Launches of ICBMs and mass launches of bombers headed towards the other side’s territory were considered by both the USA and USSR as worthy of retaliation in kind. But clarity also extended to communications.
Ambiguity was a seldom-used counterpart, and was used sparingly in tense situations. Statements could be made that were deliberately ambiguous but meant to send a message saying that situations had got so bad that nuclear weapons were now under consideration. A classic case study is the Cuban missile crisis, where there were both clear and ambiguous statements, mostly skilfully wielded by interlocutors whose nerve and intellect make them appear to be titans in retrospect.
It seems to me that the Trump administration has basically taken steel wool to the credibility coin. We cannot tell where clarity ends and ambiguity begins. We can all see that Trump does not always formulate his communications in the clearest possible way. But even the clearest language needs an unencumbered pathway to the correct recipient.
Trump’s communications in the present crisis suffers from the fact that it is often uncertain who his interlocutors are. For all of the alleged messaging between the White House and Iran in recent weeks, it is not always discernible who he is actually making agreements with. Diplomats take notes; it is clear that diplomats are absent from many of these interactions because there are not any notes as to what was actually discussed or agreed. Trump seems to have taken the tool of ambiguity and made it his primary mode of operation. Lurching from apparent agreement to dispute and back again just causes further confusion.
When you take this degree of ambiguity and apply it to nuclear firepower, suddenly deterrence does not actually work so well. The recipients of threats and intimidation may choose to not believe a threat. The entire idea of nuclear deterrence is degraded if there is not any clarity over what is or isn’t a red line and if the communications are so clouded or unreliable or inconsistent.
Taking this out of the purely Iranian context, what about a crisis with China or North Korea? The lesson might be that US nuclear weapons are either worthless or unpredictable.
If anything, the whole episode may serve to demonstrate to the world that American nuclear threats can be stared down. It is equally possible that the situation demonstrates that a country with nuclear weapons can behave as it wishes. It is not wise to promote these ideas. While American nuclear threats being empty right now might be an actual comfort in the short term, at some point, one hopes, a sane leader will re-emerge. There will be future needs for nuclear deterrence, and sabotaging it now serves no strategic purpose.
