The Korean War started when the United States declared the Korean peninsula to be outside its defensive perimeter, then changed its mind once the Communist forces invaded. The United States under the present administration has done everything it can to declare Ukraine outside the West's defensive perimeter -- withdrawing diplomats today, declaring combat forces off the table a month or so ago -- but now is mulling shifting
up to fifty thousand men into Eastern Europe as a hedge against Putin's 100,000 forces massed on Ukraine's borders.
Nor is it limited to drawing a line just this side of Ukraine.
...after years of tiptoeing around the question of how much military support to provide to Ukraine, for fear of provoking Russia, Biden officials have recently warned that the United States could throw its weight behind a Ukrainian insurgency should Mr. Putin invade Ukraine.
That is always an option, although not one generally acknowledged publicly by the President himself. Normally you have think tanks and other outsiders warn about that possibility, trusting your opponents' intelligence services to read those white papers and pass the warning along. Open acknowledgement undermines the chief advantage of such a strategy, which is plausible deniability.
Nor is this theoretical.
More than 150 U.S. military advisers are in Ukraine... [including] Special Operations forces, mostly Army Green Berets, as well as National Guard trainers from Florida’s 53rd Infantry Brigade Combat Team.
Military advisers from about a dozen allied countries are also in Ukraine, U.S. officials said.... In the event of a full-scale Russian invasion, the United States intends to move its military trainers out of the country quickly. But it is possible that some Americans could stay to advise Ukrainian officials in Kyiv, the capital, or provide frontline support, a U.S. official said.
Emphasis added. Sometimes we deploy forces as a 'tripwire,' daring enemy forces to engage them because it would mean engaging the United States military. The ongoing mission in South Korea is of that sort. Yet these forces are pledged to be withdrawn in the event of a Russian invasion, unless they stay to provide 'frontline support' to the opposition according to this nameless official.
That is exactly the kind of lack of clarity that provoked the Korean conflict. We are well behind the power curve if we want into this fight -- those fifty thousand men can't be there for a long time, and the initial commitment will only be a few battalions. Ships take a while to float. Divisions take a while to shift into place, and they can't get there too far ahead of the logistical sustainment elements they will require.
If we don't want the fight -- if letting Russia (and probably China) reassert their older claims to a larger sphere of influence than they have enjoyed during the era of the Pax Americana -- then we should be clear about where our lines really are now. There's no point whining about the Russians rolling into Ukraine if we have decided they can have it for the moment; and neither Russia nor China has the demographics to hold these extended claims for more than a generation or so.
We would not be here, of course, if the Biden administration had not come into power; their willful destruction of American energy independence, their devastation of our economy, and their humiliation of our military in Afghanistan are at the back of the present moment of weakness. Yet it is what it is; retrenchment may be necessary for the present moment. A second Korean war in eastern Europe serves no one's interests, not even Ukraine's.