I’m not sure if I follow. It’s been 3 years and Ukraine, with the support of US and EU, has lost significant territory. If US withdraws, EU/Ukraine will clearly be in a very bad situation.
EU currently doesn’t have proper air defense, military and army. It will take at least 5 years to build the required capabilities.
The US + EU is fighting by proxy (less efficient than direct), in a limited fashion, and very reluctantly at that.
Even that's been enough to extend Putin's "three day" war into three years with colossal losses on both sides, and a completely unsustainable situation in Russia.
If Russians set foot on EU soil, the game changes much for the worse for Russia.
EU currently doesn’t have proper air defense, military and army. It will take at least 5 years to build the required capabilities.