WASHINGTON -- When confronting an existential enemy -- an enemy that wants to terminate your very existence -- there are only two choices: appeasement or war.

In the 1930s, Europe chose appeasement. Today Spain has done so again. Europe may follow.

One can understand Europe's reaction in the 1930s. First, it could almost plausibly convince itself that Hitler could be accommodated. Perhaps he really was only seeking what he sometimes said he was -- the return of territory, the unification of the Germanic peoples, a place in the sun -- and not world conquest.

Today there is no doubting the intentions of Arab-Islamic radicalism. It is not this grievance or that (U.S. troops in Saudi Arabia). It is not this territory or that (Palestine, Andalusia). The intention, endlessly repeated, is the establishment of a primitive, messianic caliphate -- redeeming Islam and dominating the world. They have seen the future: Taliban Afghanistan, writ large.

Moreover, Europe in the 1930s had a second excuse. The devastation of the First World War, staggering and fresh in memory (France and Germany lost a third of their young men of military age), had made another such war unthinkable. This does not excuse appeasement -- it cost millions more lives in the Second World War -- but provides context, and possibly humility. One has to ask oneself: Am I sure I would not have chosen the cowardly alternative?

Nonetheless, it was still the cowardly alternative. And today, Spain has chosen it -- having suffered not Europe's 20 million dead of the First World War, but 200 dead in the Madrid bombing.

The Socialist Party placed the blame for the attack not on the barbarians who detonated the bombs, but on the Spanish government that stood with the United States in its war against the barbarians. The Spanish electorate then voted into office the purveyors of precisely that perverse view.

Spain will now withdraw from Iraq, sever its alliance with America and, as Prime Minister-elect Zapatero has promised, ``restore magnificent relations with France and Germany.''

Nonetheless, Spain is just Spain. The really big prize is Europe. Which is why the most ominous development of the week was the post-Madrid pronouncements of Romano Prodi, the president of the European Commission.

``Clearly the conflict with the terrorists is not resolved with force alone.'' Sounds reasonable until you hear Prodi's amplification of the idea just two days earlier. ``We know that international terrorism wants to spread fear,'' said Prodi. ``Fear generates not so much justice, but rather vengeance, which chooses war to answer the need of security. ... We become prisoners of terror and of terrorists.'' In other words, making war on terror is unjust, fearful, mere vengeance, and ultimately a victory for terrorism. Continued...