What's the opposite of a gift that keeps on giving? A mistake that keeps metastasizing.

Which pretty much sums up the US role in the Middle East. Beginning with the CIA's 1953 overthrow of Iran's democratically elected president and continuing through the multiple regime changes and invasions of recent years, various American governments have behaved like they both understood that region and had the power to mold it into a docile client that pumped oil, suppressed dissent and otherwise caused no trouble.

Instead, each intervention turned up the heat on an already-boiling pot of corruption, sectarian rivalry and geopolitical anger that has finally erupted into regional civil war. The whole world, at long last, understands that the situation is beyond both US understanding and control.

And that's the good news.

The really scary part of the story is that Russia has jumped -- decisively -- into this vacuum and is building a coalition to take over the Middle East. In partnership with Iran and China it's propping up Syria's dictator and bombing both ISIS and US-trained rebels back beyond the stone age. The next step will presumably be to bring Saudi Arabia into line and thus dominate the region's oil reserves. Israel, in this scenario, has no good options.

Unless, of course, the US pushes back, which will mean escalating from Russian and US proxies shooting at each other to actual Russian and US soldiers going at it, with China and Iran helping the former and Saudi Arabia the latter. This is a nightmare scenario on every level, and it's closer than most people seem to think. Here's a sampling of headlines from just the past couple of days:

Syria conflict: Nato warns Russia on air strikes
Syria conflict: Turkish jets intercept Russian plane
Syrian insurgents vow to attack Russian forces as Moscow hints at ground role
U.S. sees Russia readying ground campaign in Syria
Syria's 'moderates' have disappeared... and there are no good guys
Russia's airstrikes in Syria are playing well at home
A tale of two strategies: Russia destroys ISIS command, US hits Afghan hospital
Obama up against growing support for a no-fly zone in Syria

Just as there was a chance in the 1990s to get developed-world entitlement programs under control and we blew it, there was once a chance to let the Islamic world work out its differences, have its Reformation, and emerge as a more-or-less stable, comprehensible power. But we blew that monumentally as well.

Now the US is financially and politically exhausted, with neither the money nor the will to expend trillions of dollars and tens of thousands of lives to impose "peace" in a place where the word can't even be defined. Yet, as the last headline says, support for a Syrian "no-fly zone" is growing -- in air space that includes Russian jets.

In some ways today's situation is reminiscent of the late 1930s, when the last thing anyone outside of Germany wanted was another big war, but that's exactly what they got.