The belief that Europe as a continent is going to back Ukraine militarily is hardly surprising. It follows in the development of President Putin’s limited field of view.
He only sees as far as his own borders in both fact and as a matter of principle. The uncertain status of Ukraine’s border is giving him reasons to say more.
He may indeed find his soldiers are returned heavier fire or targeted by more powerful strategy. This isn’t the cause of a wider war.
Putin needs to have his plan for greater domination shut down, and holding to lines isn’t the answer. If he fears it, it will come.

