Standoff: President Trump is locked into a war of words with Kim Jong-un as the world watches. Photo/AP
We have to face facts: there is no US federal government any more in the normal sense of the word. Social Security payments still get made and the 2.79 million federal civil servants still get paid, but there is no such thing as US government policy - especially foreign policy. Take the US Defence Secretary, former General James "Mad Dog" Mattis.
Despite his nickname, Mattis is a rational human being who thinks that the proliferation of nuclear weapons is a bad idea. He knows that it's too late to stop North Korea from getting them, but he also knows that it is still possible to stop Iran from doing the same. In fact, the job is done: Iran signed an agreement in 2015 that takes the whole issue off the table for 10 years.
Mattis is well aware that his boss, President Donald Trump, regularly fulminates about how bad the Iranian "deal" is and keeps hinting he will cancel it - in which case, of course, Iran could go ahead and get nuclear weapons in a year or two.
So he put his own job at risk last week by telling the Senate Armed Services Committee that the United States should keep its word and abide by the agreement with Iran.
Now he's waiting for President Trump's next tweet, which may well repudiate what he said. Trump won't fire Mattis - he prefers to humiliate people in tweets until they quit - but his usefulness as Secretary of Defence is nearly at its end.
Foreigners, including Iranians, know Mattis is serious, but they also know that he does not speak for the president. Trump will do whatever he likes, so why bother talking to Mattis?
It's just the same with Rex Tillerson, the Secretary of State.
Two weeks ago he said the United States has "lines of communication" open to Kim Jong-un's North Korean regime.
The subtext was clear: don't worry about a nuclear war, folks.
We're talking to them (or about to talk to them, or talking about talking to them), and there's still time for a deal that defuses the whole crisis.
It's not clear that that's actually true, if the deal must include North Korea giving up its nuclear weapons and missiles.
Kim is well aware of what happened to other people who defied the United States but did not have nuclear weapons, like Iraq's Saddam Hussein (dangling from the end of a rope) and Libya's Muammar Gaddafi (a bayonet up the backside), so he is strongly motivated to hang on to his.
But it is what Tillerson should say now, and it might help.
Trump didn't wait 24 hours before he tweeted: "I told Rex Tillerson, our wonderful Secretary of State, that he is wasting his time trying to negotiate with Little Rocket Man ... Save your energy Rex, we'll do what has to be done!"
Like what? If negotiations are a waste of time, then the only alternative is force.
Does Trump mean he's going to attack North Korea (which would almost certainly involve the use of nuclear weapons)? Of course not. He doesn't mean anything; he's only venting, as usual.
He has no idea what he's going to do about North Korea, if anything. He doesn't even know what he is going to think or say tomorrow.
The trouble is that Kim Jong-un probably doesn't realise how aimless and inconsequential Trump's tweets usually are. What Kim sees is most likely a death threat to him by the ruler of the most powerful nation on Earth.
He has seen a dozen more messages like it in the past six months, and he must be looking frantically for a way out.
Talking to Tillerson might have shown him a way out, or at least bought him some time, but he's definitely not going to talk to a diplomat who has been repudiated by his own president. As Foreign Secretary, Tillerson is toast.
There have been calls in Washington for Tillerson to resign to avoid further humiliation, but others hope he will swallow his pride and stay in office as long as he can to postpone the appointment of a super-hawk like John Bolton or Nikki Haley.
In fact, it probably doesn't matter very much either way, because they would find that the Boss is undermining and discrediting them too.
In the circumstances, it's not surprising that America's allies and its opponents are both coming to the conclusion that they will just have to ignore the US and make their deals without it. Iran, for instance, has said that it might stick by the nuclear deal if all the other signatories stay loyal to their commitments.
Trump is a problem, of course, but for all his threats and boasts he doesn't actually do much. It could be a viable strategy for the next three years.
■Gwynne Dyer is an independent journalist whose articles are published in 45 countries.