In reality, denouncing “radical Islam” offers little guidance for America’s actual policy dilemmas. How does calling the enemy by its “real name” help determine whether the United States should take a harder or softer line toward the government in Baghdad? We need its help to retake central Iraq from ISIS, but its Shia sectarianism drives Sunnis into ISIS’ arms. Or how would this linguistic pivot help determine whether the best way to weaken ISIS in Syria is by backing Bashar Assad or seeking his ouster?

After 9/11, hawks backed up their aggressive rhetoric with aggressive policies. At their behest, America invaded and occupied two Muslim countries. Today, by contrast, with land invasions effectively off the table, the rhetoric has become largely an end in itself. What Republicans are really declaring war on is “political correctness.” They're sure that liberal sensitivities about Islam are hindering the moral clarity America needs to win. Just don't ask them how.

But it's worse than that. Because far from providing the moral clarity Republicans demand, saying America is at war with "radical Islam" actually undermines it. How can a term provide clarity when it's never clearly defined? If America is at war with "radical Islam," does that include Saudi Arabia, a key US ally that for decades has both practiced and exported a radically illiberal Wahhabi creed? Does it include Iran, a semi-theocracy that has sponsored "radical Islamic" terror against the US but is our de facto ally against ISIS? Does it include Muslim Brotherhood parties like the one that briefly held power in Egypt, which run in democratic elections but want a government based on Islamic law? Listening to some GOP rhetoric, you might think the answer is yes. But to suggest the US is at "war" with key allies like Saudi Arabia and Egypt strips the term of any real meaning.

ISIS and Al Qaeda in the Arabian Peninsula are actual organizations. Reasonable people can delineate where they begin and end, and thus craft specific strategies for fighting them. Good luck doing that with “radical Islam.”

As so often happens in today’s GOP, the Republicans demanding a war against “radical Islam” are working off a false analogy with the Cold War. Since Ronald Reagan’s “moral clarity” against communism supposedly toppled the Soviet Union, America must now do the same with “radical Islam.”

But, in fact, the United States was most successful when it did not see its enemy as “communism.” It was the belief that America must battle communism itself that led the Kennedy and Johnson administrations into a war against a communist regime in North Vietnam that posed no real threat to American security. The US fared far better when it limited its focus to one specific regime, the Soviet Union, and made alliances with other communist governments in order to weaken it. In the late 1940s, the Truman administration worked with communist Yugoslavia to undermine Soviet control of Eastern Europe. And under Richard Nixon, Washington cozied up to Beijing, which despite being even more ideologically zealous than Moscow, helped the US contain Soviet power. Reagan, for all his anti-communist rhetoric, maintained America’s de facto partnership with China because his real target was the USSR.