"History does not repeat itself, but it often rhymes," said Mark Twain.
Observing the uprising in Syria, the atrocities, the intervention by rival powers, it all calls to mind the Great Rehearsal for World War II, the Spanish Civil War.
The war began in 1936 with an uprising in Morocco of Spanish Nationalists against a Madrid regime seen as anti-Catholic, Marxist and Trotskyite. Vladimir Lenin had predicted that Spain would be the second Soviet republic in Europe.
The war would last three years, with Joseph Stalin providing aid to the regime, Benito Mussolini sending troops to fight on the side of Gen. Francisco Franco and Adolf Hitler sending his Condor Legion. The bombing of Guernica by the Legion, commemorated in the famous Picasso painting of that name, would be regarded as the great war crime of the conflict.
Yet Guernica was child's play compared with what was to come with the Blitz, Berlin, Dresden, Tokyo, Nagasaki, Hiroshima. The Nuremberg Tribunal would wisely rule out terror bombing of cities as a war crime for which Nazis could be prosecuted and hanged.
As America has declined to intervene in Syria, FDR declared neutrality early in the Spanish Civil War, outlawing any sale of weapons to either side.
In 1936, as the Spanish war erupted, FDR spoke for his country:
"We shun commitments which might entangle us in foreign wars; we avoid connections with the political activities of the League of Nations. ... We are not isolationists except insofar as we seek to isolate ourselves completely from war."
America emphatically agreed.
Today, it is the bitter fruit of Iraq and Afghanistan that explains our reluctance. Then, it was 116,000 American dead in places like the Argonne and Belleau Wood -- which had produced a Carthaginian peace at Versailles and set the table for Hitler -- that had left us with ashes in our mouths.
Two battalions of American volunteers did go to Spain to fight on the side of the regime. In 1947, veterans of that "Abraham Lincoln Brigade" would be put on the Attorney General's List of Subversive Organizations.
In Spain, the struggle was ideological and religious -- Nationalists and Catholics against socialists, communists and anarchists.
In Syria, too, it is religious -- the Alawite Shia regime of Bashar Assad battling an uprising centered in the Sunni Muslim Brotherhood.
As Europe in 1936 contained democracies, dictatorships of the fascist and authoritarian right, and a Stalinist left, today's Middle East contains democracies, monarchies and dictatorships.