That was the part of Spain's Civil War history that resonated with Weiss's piece on Syria.

The Popular Front splintered. The glue of anti-fascism was not strong enough to overcome the animosity that divided Proudhon, Marx, Bakunin and their successors. They turned against one another. Democracies looked on. Fascism won. Could that be Syria's fate? As the Syrian rebels splinter, unable to overcome their differences to achieve the common goal of toppling Assad, democracies have assumed the role of bystanders. Fearful of an al-Qaeda victory, they may let Assad win, come what may.

Earlier this year, in the pages of Standpoint, I addressed the analogies between the Syria conundrum and the Spanish Civil War. But they deserve more scrutiny because of the sudden turn of events in Syria in September, and the likely rapprochement between the US and Iran after Rouhani's visit to New York.

Less than a year into the Spanish Civil War, German and Italian warplanes bombed the town of Guernica in the Basque region. The wanton slaughter of civilians was a harbinger of the Nazi total war that would engulf Europe two years later. The suffering of Guernica was immortalised by Picasso's homonymous painting, which toured the world shortly after its completion drawing public attention to the horrors of the Spanish Civil War. The painting, now in the Reina Sofia museum in Madrid, is a symbol of all anti-war causes. And like many other such testimonials, it failed to move the world's conscience to act. If anything, it scared Western audiences into appeasement — for as long as they could sacrifice someone else's future to Hitler's appetites, diplomacy was preferable to conflict.

Look at Guernica then, but think of Assad's ruthless chemical weapons assault on his own citizens in August in Damascus's eastern suburbs. Assad is still there — his crime will go unpunished and his patrons have now been dignified with an indispensable role in finding a negotiated solution to the Syrian conflict.