I would argue that we did our bid for European stability, that everybody thought Ukraine would be quickly overrun. We don’t need to defend every inch of Ukrainian soil for us to consider it a success and a deterrent. We did far more here than Obama did to protect crimea.
Yes we raised the stakes considerably. Russia thought the Ukraine operation would be over in weeks.
Fast forward a few more years. Russia is encircling Kiev. Are we supposed to put American boots on the ground? Give them tactical nukes? Wouldn’t giving up then just “teach them” the same thing?