We don't know who will win in Syria, but we know who will lose.

Michael Ledeen writes,

History may not quite repeat itself, but the war in Syria — invariably, “the Syrian Civil War” — is eerily similar to the “Spanish Civil War” in the mid-1930s.

He goes on to show how

events in Spain prefigured World War II. Just as Hitler, Mussolini, and Franco were determined to win at all costs, so Putin, Assad, and Khamenei are concerned only with slaughtering everyone on “the other side” and keeping the regime in Damascus in power.

Ledeen warns of the consequences of Obama's "lead from behind" strategy, comparing it to the appeasement strategies followed by British, French, and Americans prior to World War II.

Hitler and Mussolini, who had not previously shown great interest in a military alliance, were drawn closer, laying the basis for the Axis. And the manifest weakness of the free nations encouraged both fascist dictators to behave more aggressively in the future, as our weakness in Syria has so greatly encouraged the Russian and Iranian dictators today.

Seemingly forgetting about John McCain for a moment, Ledeen asserts,

Our leaders today are striving mightily to close their eyes and ears to the acts and words of war aimed at us from the new totalitarians of radical Islam and a revived pseudo-revolutionary Communism. Just as Spain offered a chance to humiliate Hitler and Mussolini, so Syria offers the chance to deliver a deadly blow to Putin and Khamenei. But no American leader seems to be listening to the chants of “Death to America” from Tehran to Caracas.

Ledeen links to Emanuele Ottolenghi, who makes very similar arguments in a piece at Foundation for Defense of Democracies.

Our exercise in self-sidelining is as myopic as it was in the 1930s. Unless there are no winners, we will be left to deal with the consequences of either regime survival — an Iranian victory — or a jihadi-dominated new order — a Western defeat.

We will no doubt protest that a third option was tenuous at best, rather than asking ourselves what could have been done to make it viable. By then, it will be too late — because, much as in 1936, our conviction is weaker than that of our adversaries. They know what they want and they are ready to pay the price. We don't — and we would prefer it if the UN paid the bill.