The reasons to keep Russians wars in check has more to do than with morality. The threat that Russia will invade other nearby countries for lebensraum is currently feeling much more real for all countries bordering Russia.
The US is unlikely to invade Poland in order to displace the polish people with Americans. To some degree a war over oil resources feel much less threatening to countries than a war for lebensraum, especially for countries which don't have a lot of oil resources. Every nation however has land, and thus every nation is a target when a country like Russia is after territory. This is a big reason why a lot of countries around Russia is currently increasing their military budgets, loosing more money on that then any losses to the economy from not buying conflict resources from Russia. If you are pumping your money into the military, it makes economical sense to not fund the military threat you are defending against.
The US is unlikely to invade Poland in order to displace the polish people with Americans. To some degree a war over oil resources feel much less threatening to countries than a war for lebensraum, especially for countries which don't have a lot of oil resources. Every nation however has land, and thus every nation is a target when a country like Russia is after territory. This is a big reason why a lot of countries around Russia is currently increasing their military budgets, loosing more money on that then any losses to the economy from not buying conflict resources from Russia. If you are pumping your money into the military, it makes economical sense to not fund the military threat you are defending against.