Question.
If Greece went back to the drachma, would it be worth the same as the Soviet ruble during the Cold War? The equivalent of Monopoly money in the international markets?
Correct. The quality of a nation's currency in International trade is determined by the quality of investments that can be bought with it. Anyone investing in Greek assets of any kind nowadays is simply asking to be robbed. FYI this is also why going on the gold standard wouldn't make the ruble or the renminbi the dominant international currency (though it would be good for the Russian or Chinese economies).
“If Greece went back to the drachma, would it be worth the same as the Soviet ruble during the Cold War? The equivalent of Monopoly money in the international markets?”
Or less.