Open conflict between Russia and the United States is heating up in Syria. After American forces shot down a Syrian fighter jet, Russia suspended use of an Obama-era communications line used to prevent collisions and conflict, and threatened to shoot down American planes.

America's Syria policy was and continues to be absolutely moronic. But this alarming development is also a reminder that there is simply no alternative to diplomatic engagement with Russia, the world's only other nuclear superpower. That's something both the American military, and liberals fired up over Trump's Russia scandal, would do well to remember.

In the discussion about climate change risk management, I have argued that somewhat unlikely disaster scenarios deserve serious consideration, because it's worth a substantial cost to avoid even a small chance of a huge harm. (It's basic insurance reasoning.) The same is true of nuclear war.

An all-out nuclear exchange between the United States and Russia is one of the few things that could threaten human extinction. Hundreds of millions, perhaps billions, would be killed in the immediate attack, blowing the world economic system apart, and beginning what would probably be several years of nuclear winter, devastating agriculture. People might survive in remote locations — perhaps Australia and New Zealand — but it's not at all guaranteed in such an extreme scenario. It would be the worst disaster in history, by several orders of magnitude.

Such a possibility gets less attention than climate change these days, I think, because we don't have to do anything to avoid it — merely preserve the mutually assured destruction framework that carried us through the Cold War, despite a few close calls. Ultimately a nuclear conflict would be the worst imaginable strategic outcome for both nations, and so both nations ought to be able to avoid it.

But, as we saw during the Cuban Missile Crisis, sometimes an escalating, high-stakes conflict can bring the worst-case scenario closer and closer. As Robert McNamara said regarding his experience as secretary of defense during the crisis:

At the end, we lucked out. It was luck that prevented nuclear war. We came that close to nuclear war at the end. Rational individuals — Kennedy was rational, Castro was rational, Khrushchev was rational — came that close to total destruction of their societies. And that danger exists today. The major lesson of the Cuban Missile Crisis is this: The indefinite combination of human fallibility and nuclear weapons will destroy nations. [The Fog of War]

Ultimately what defused the crisis was a diplomatic contact between Khrushchev and JFK (in particular a remarkably candid and vivid letter from the Russian premier), and a bargain that if the Soviets took the missiles out of Cuba, the U.S. would promise not to invade Cuba, as well as a secret promise to take similar missiles out of Turkey.

So what are we doing in Syria to justify ratcheting up tensions with Russia? The prospect of nuclear warheads a mere few dozen miles off the American coast was at least a comprehensible strategic threat. In Syria there is not only no strategic threat, there is not even a realistic American objective of any kind.

Russia has a clear goal: Prop up the Assad regime, but avoid being drawn too far into the conflict. America is, as far as anyone can tell, fighting ISIS, attempting regime change without invasion, arming some rebels but fighting others, and trying to help Kurdish militia without annoying Turkey too much. Both Trump and the foreign policy establishment (a.k.a. "The Blob") childishly refuse to admit that most of these goals are incompatible with one another.

In reality, I don't think any of the actual actions really suffice to explain why America won't stop meddling in Syria. We're there because The Blob has a hysterical obsession with the Middle East, because interventions are a lot harder to stop than they are to start, because President Trump is an absolute chump, and above all because of the almost universal article of faith that the American military can do no wrong.

There's not much that can be done about this in the short term. Remarkably, Secretary of State Rex Tillerson does seem to grasp the need for diplomacy, with the construction of a new diplomatic framework for handling tensions with Russia, as BuzzFeed News reports. But there is little sign Trump is even capable of paying attention to such things, and less that Tillerson's badly understaffed agency will be able to implement it in a systematic fashion.

In any event, it's worth emphasizing that not only is America pouring money and lives down the drain in Syria for virtually no reason, we are also increasing the chance of extremely risky confrontation with Russia — during the presidency of the most inept person ever to hold the office. (The mind reels at the idea of this president attempting to navigate a serious diplomatic crisis.) If Congress had any sense at all, they would be asserting their constitutional duty to oversee the use of military force — remember there has never been any congressional authorization of Syrian intervention — and liberals would be a bit more careful with anti-Russia diatribes.

Even if the Russians did intervene to elect Trump, there will still be no alternative to diplomacy with a nuclear superpower, for now and the foreseeable future.