It's not unreasonable to take such a position, yes.
Look, if you believe that:
a) humanity is headed toward sustained peace
b) a transition from the current world order to a peaceful one is better done in an orderly and adult fashion
...then yes, at some point we all need to back away from participation in the legacy systems, right down to the drywall.
My observation, especially of the younger generations, is that belief in such a future is more common than it has ever been, and it's certainly one I hold.
Actions within that system may be unethical: certainly nobody is defending what America did to Cambodia, or countless other war crimes. But you're painting participation in the system as unethical. Therefore, Ukrainians defending their homeland are unethical.
Let me reframe what you said in terms of christianity:
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If you believe that:
a) Jesus is our savior
b) The salvation of humanity depends on accepting (a)
...then yes, at some point everyone needs to back away from other religious systems, right down to atheism.
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I'm not trying to make light of what you believe, but framing others' participation in a system you don't believe in as unethical is exactly what leads to oppression of religious minorities and other outsider groups. It's a tactic of religion, not reason.
