Former Vice President Mike Pence warned that American troops will be forced to fight Russia if it succeeds in its efforts to conquer Ukraine and win the war.

As Just The News reported, Several alliance members already directly border Russia, though should Moscow annex Ukraine, it would brush up against several more. During an appearance on NewsNation, Pence opined that a bellicose Moscow was likely to cross international boundaries and provoke a conflict with NATO.

“I’m convinced that if the Ukrainian military doesn’t stop and repel that Russian invasion, it’s not going to be too long before that Russian army crosses a border that our men and women in uniform are going to have to go and fight under our NATO Treaty,” Pence said.

“I truly believe it. Whether that’s Estonia, Latvia, Lithuania… Poland, I don’t know.”