Indeed. Free trade is completely separate from a free market. Both Nazi Germany and the USSR were non-market economies that practiced free trade with each other. Non-market economies are mercantilist at their core though, and if allowed free trade with a free market will strip that market bare.
Germany was prohibited from almost all things military.. the Soviet Union offered them a way..
"The Soviets offered Weimar Germany facilities deep inside the USSR for building and testing arms and for military training, well away from Treaty inspectors' eyes. In return, the Soviets asked for access to German technical developments, and for assistance in creating a Red Army General Staff."
(From a wiki source.) The Soviets with German technology helped build another German war machine even before Hitler.
Today of course there are no such duplicitous and evil schemes.. the Communist Party has indeed faded away and the workers in the paradise of the democratic Republic of China don't care about being a great power they just love to make inexpensive and great things for the Americans. . . . all is well.. except for the problems caused by the "protectionists nut jobs." :)