While it is an exploit to keep consumer goods down... isn't this done in real life? To make sure this stays on topic, the Cold War right after WWII would be an example. ... So I guess in MP it's a no, but if you can justify it for SP, it's not one of the worst exploits.
Edit: I have an example. As Japan, I'm in the Axis, but I got the event to stay neutral with USSR. But I can lend my planes/army to Germany and they'll fight. In real life, if the USSR found out that Japanese were attacking them in violation of neutrality... it would not be allowed. Expeditionary forces...for game play, it's a benefit, but realistically, many of the ways players use them would never have been allowed in real life (namely Spanish Civil War providing more than 1 division).