Free Trade = Peace?

I have had many friends who advocate no war through free trade. But I wonder how far that goes. Say in 1950 we ignore the USSR's exploits in northern Europe. So that has happened. Then we ignore the USSR's invasion of eastern Europe. So what, we don't trade with them. Then they take over the entire Eastern hemisphere, not our problem, except, who do we sell to then? And then they take over everyone but us. Is that good for our trade?