If its advance is halted, Russia will still occupy much newly seized Ukrainian territory, especially in the country’s south along the Sea of Azov and the Black Sea. It will also still possess Crimea and control the breakaway regions of Donetsk and Luhansk. Understandably, Ukraine is not going to settle for that. President Volodymyr Zelensky will want to retake Ukrainian territory and restore the borders promised to it in the 1994 Budapest Memorandum.

So that’s what Ukrainian victory means. And for the West, backing that effort would require much different levels and types of military support. Ukraine cannot retake its conquered lands without offensive weaponry — meaning lots of tanks, armored personnel carriers and artillery. It also would require an extensive supply of airplanes, both fighters and close-support planes capable of bombing Russian ground troops, along with modern, large-scale anti-air weaponry.

Providing all this, of course, would put the United States and its European allies in a much more aggressive posture toward Russia.