The White House press secretary, Sean Spicer. Mark Wilson/Getty Images If President Donald Trump gets us all killed, it's going to be through a chain of events like what we have seen over the past day.

On Thursday, the White House press secretary, Sean Spicer, floated the possibility that GCHQ — a British intelligence agency — had spied on then-candidate Trump at the behest of President Barack Obama.

He said this on the basis of a story from former New Jersey Superior Court Judge Andrew Napolitano, a conservative media personality who is also a 9/11 truther.

Ultimately, Spicer said this because the president decided two weeks ago to claim on Twitter, in a fit of pique, that Obama had illegally given an order to "tapp" his phones at Trump Tower. And because Trump is congenitally incapable of ever admitting error, his White House has been sent into a frenzy for two weeks trying to justify his invented claim instead of backing down.

The British are furious, as of course they should be. What Trump's staff accused them of would be a violation of an informal agreement that the "Five Eyes" intelligence-sharing countries avoid spying on one another's citizens.

On Friday, the London-based newspaper The Telegraph reported that National Security Adviser H.R. McMaster provided a "formal apology" to the British government. But a White House official characterized it quite differently: Officials explained to the British that Spicer "was simply pointing to public reports and not endorsing any specific story."

That is, Spicer wasn't accusing the British of spying on Trump. He was just asking questions.

We are literally having an international incident because our president was mad on the internet.

Obviously, a stupid and gratuitous diplomatic spat with the British is not going to lead to an exchange of nuclear saber rattling. But Trump's delusional thinking, unwillingness to admit fault, and fragile male ego are not limited to his relations with our close allies.

What I most fear about Trump's presidency is that he will blunder into a nuclear war. If he does, it will look something like this, but with a less-forgiving country than Britain. Perhaps, for example, it could be North Korea, a country doing its best to stir the pot.

It's not that I think Trump will get offended and immediately order a nuclear strike on a country that offends him. I believe that he could be talked out of that. I even believe that the military chain of command would refuse such a ridiculous order.

Rather, it is that Trump will create a chain of unnecessary provocations, escalating situations that should be de-escalated, until we end up in a nuclear exchange — perhaps even one in which we are making the second strike.

If you think about international incidents on a scale from "easy to de-escalate" to "hard to de-escalate," "stupid accusation against GCHQ" is way out on the "easy" end. And yet, this White House cannot even fix that one correctly.

As you watch the White House fail to fix this easy-to-fix screwup, do you have any confidence in it to manage a confrontation with North Korea with a clear eye toward avoiding millions of deaths on the Korean Peninsula? What will happen if Trump feels de-escalating the situation in Korea will involve a loss of face for him?

Trump talks about nuclear war as though it is a grim inevitability. It's not — nuclear war is avoided through careful and responsible diplomatic maneuvering by nuclear powers, both friendly and hostile. But "responsible diplomatic maneuvering" is not Trump's strong suit.

As I watch Trump blunder with Britain, I am terrified that his handling of the Korean crisis might lead to the deaths of many, many, many, many people.

Of course, it probably won't. But the probability that it will is far too high. Of the unacceptable tail risks of the Trump presidency, this is by far the scariest and most unacceptable. And it's a bigger deal than healthcare, the "skinny budget," or any other news this week.