The Peninsular Campaign is probably the best historical analogy here, but the Peloponnesian War can approach it from another angle. Moscow’s strong-arm tactics are reminiscent of Athens’ hegemonic “alliances,” and the U.S. can play Sparta in building a league of free states resisting the “growing power of Athens” (Thucydides). The big difference is that Russia is far weaker than Athens was, but the strategy, similar to Britain vs. Napoleon is mostly the same; chip away are your opponent and wait for him to make mistakes that you can exploit (the Syracuse expedition or Napoleon’s invasion of Russia). Britain couldn’t do decisive damage to France’s logistics, but Russia needs the energy exports to survive. Richard noted that there are multiple ways into the Bosporus. Similarly Sparta finally defeated Athens with a large asymmetric coalition of more or less free states. Her ultimate victory in taking the port at Pireaus came after grabbing a number of islands scattered across the Aegean.