What does Russia have that US would want to fight a proxy war over? Certainly isn’t technology or natural resources.
Now that Ukrainian resolve to fight is cooling off, you can see Trump administration planning more wars - in Palestine, Yemen, Iran, Venezuela..
These operations benefit wealthy class in the U.S. (the profit from government contracts) as well as a fat layer of middle class Americans who are involved in making wars.
Every country that exports weapons has this incentive, including Russia, but the U.S. is by far the largest country producing weapons it doesn't need internally. International arms trade should be IMHO completely banned, because it gives (capitalist) countries strong motivation to cause wars. It's a negative externality.