Although leaders of NATO countries have sought to sanction Putin and Russia over the invasion and have offered military assistance to Ukraine, President Biden has repeatedly emphasized that U.S. forces would not be deployed in Ukraine. The only way analysts can foresee a war between the U.S. and Russia would be if Putin’s forces attacked a NATO country. He could feel emboldened by his foray into Ukraine and attack vulnerable European countries that are not NATO members, which could put his forces in closer proximity to NATO’s.