I would also say the Mediterranean but you'd have to use a bit of the Atlantic to get there. You couldn't use any rivers. Also, since unification, there is no longer a West Germany - it's just Germany.
Its the Mediterranian ocean with borders north Africa and europe
A traveler moving from West Germany to Greece, while crossing only NATO countries, would need to cross the Mediterranean Sea. Starting from Germany, the route would involve traversing through NATO nations such as Austria or Hungary before heading to Greece. Therefore, the body of water in question is the Mediterranean Sea.
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