>

Okay, what's stopping the U.S. from sending "Thoughts and Prayers"?
"De Facto" literally means not in accordance to law, but effectively the same.  Nearly every single NATO member is providing military assistance to Ukraine.  The effective difference between the aid they are retrieving and full NATO membership could be debatable since NATO doesn't require member nations to send ground forces or control airspace or even declare war with the invading nation. >


NATO doesn't require member nations to send ground forces or control airspace or even declare war with the invading nation.

What good is Article 5, then, if all member nations can decline to declare war? >

If article 5 is invoked all of the members of NATO will come to the attacked country’s defense with such action that they deem necessary. That have to contribute in one way or another but they are not all required to or expected to fully mobilize their militaries and send them to war because there are NATO members whose militaries are irrelevant.  Like… if NATO went to war with Russia a country like Croatia really has nothing meaningful to contribute militarily so they would find other ways to contribute.