In case there is any doubt that this is effectively the end of the NATO alliance. Europe is now on its own vis-à-vis Russia as there will be no Article 5 backup by the U.S.

U.S. Department of Defense, "Hegseth Calls on NATO Allies to Lead Europe's Security, Rules Out Support for Ukraine Membership" https://www.defense.gov/News/News-Stories/Article/Article/4064571/hegseth-calls-on-nato-allies-to-lead-europes-security-rules-out-support-for-ukr/

«As an alternative to granting Ukraine NATO membership, Hegseth said that any security guarantees for Ukraine "must be backed by capable European and non-European troops."

"If these troops are deployed as peacekeepers to Ukraine at any point, they should be deployed as part of a non-NATO mission, and they should not be covered under Article 5 [of the NATO treaty]," Hegseth said, adding that there must also be robust oversight of the line of contact from the international community.

"To be clear, as part of any security guarantee, there will not be U.S. troops deployed to Ukraine," he said.»