Incompetence at the highest levels of government, particularly in the arenas of diplomacy and national security, can have enormous consequences.

When that incompetence is blended with blind arrogance, with a conviction that gut instinct is a suitable, even preferable substitute for strategic thinking, the likelihood of a major blunder grows exponentially. It can easily lead to a war, or multiple wars, that are unnecessary and tragic and that take tens or hundreds of thousands of human lives.

That appears to be the trajectory that we’ve now headed down, with no one in power capable and willing to steer a more rational course.

At the moment, as you know, we have no secretary of state. We also have no ambassador to South Korea and no special envoy to Korea. In addition, the U.S. national security adviser is by many accounts a lame duck awaiting word of his dismissal via the customary mode of Twitter.

As a result of that vacuum, when the South Korean foreign minister visits the White House later this month in the midst of a highly fraught international crisis, the principle on the American side of the meeting will be ... Ivanka Trump.

And no, I am not making that up. According to the South Korean foreign ministry, no date has yet been set, but "there's speculation the two will exchange opinions regarding the forthcoming summits between the two Koreas and between the U.S. and the North."

The United States, the most powerful nation the world has ever known, will have a fashion-shoe designer and Manhattan socialite leading nuclear strategic negotiations with an important ally. What could go wrong?

But wait, it gets worse. Trump’s current national security adviser, Lt. Gen. H.R. McMaster, is being shoved aside by Trump, reportedly because the president believes that “McMaster is too rigid and that his briefings go on too long and seem irrelevant.” “Too rigid,” I suppose, is Trump-speak for someone willing to try to frustrate Trump’s worst instincts and impulses, while “long briefings” are those that last beyond Trump’s two-minute attention span.

In McMaster’s stead, Trump is reportedly considering John Bolton, the far-right foreign-policy “expert” who never saw an international situation that couldn’t be resolved with bombs and bullets. If Trump gets frustrated by the pace of negotiations with North Korea and wants to exercise his military option, Bolton would be there to egg him on. When Trump insists on undoing the Iran nuclear deal, Bolton will again be there as the devil on his shoulder, praising it as a step that no other president would have the guts to take.

Publicly and privately, Trump continues to make clear his commitment to breaking the Iran deal. But to date, I have seen no reasonable or even plausible explanation of what happens once that step is taken. Any attempt to impose something tougher would require the cooperation of Germany, France, Great Britain, Russia and China, the nations that worked with us for years to negotiate the original treaty, and the Trump administration has not exactly built a relationship of trust and confidence with those countries.

Reneging on the Iran deal would leave us one alternative, military intervention, and if we take that course we would do so unilaterally, over strident opposition from most of our allies and most of the world. It would make the Iraq War seem like the invasion of Grenada.

Unfortunately, this is the same sort of sophisticated, multi-level thinking that, when applied to the opioid crisis here at home, produces a proposal to execute drug dealers. When applied to the problem of mass school shootings, it produces a proposal to arm teachers. But when applied to the world of international diplomacy, the consequences are much much greater.

Think about it: On one side of the world, the Trump administration is trying to convince the North Koreans that they can safely negotiate away their nuclear arsenal, that once they agree to disarm themselves, the United States can be trusted to keep its commitments not to invade and to allow North Korea to enter the international community.

Meanwhile, on the other side of the world, the United States is trying to renege on a deal with Iran, a country that DID negotiate away its nuclear ambitions, and that by all accounts has abided by the terms of that deal in good faith. The contradiction is glaringly obvious to North Korea and to the likes of McMaster and Rex Tillerson, the departing secretary of state, but apparently not to the president.

All of his life he has been a man who wants; all of his life he has surrounded himself with people who will fulfill those wants, no matter how unreasonable. And all of his life, he has managed to ensure that when the bill comes due, somebody else pays the price, no matter how heavy.

All that has changed is the scale, and that is everything.