If the USA (or another western country) wants to help Ukraine without sending troops, one thing it can do is to convince Russian soldiers in Ukraine to defect, for example, by promising a green card to any soldier who abandons his post. As many Russian soldiers are poor, and do not entirely support Putin, this deal might be attractive to them. Clearly, only few soldiers will be able to get out, but even if one or two soldiers escapes, this might affect the morale of remaining soldiers. Instead of thinking how to beat the Ukrainians, they might think how to escape.
Question: does it break any international law or treaty, to pay soldiers of another country to abandon their duty? Are there any other repercussions to this idea?