DANIEL PIPES: Iran vs. Turkey, the MidEast’s Perpetual Rivalry.

Their most major difference concerns the attitudes of their subjects. Whereas Khamene’i enjoys the support of only about 15 percent of the populace, Erdoğan can count on some 45 percent, affording Erdoğan a legitimacy and confidence that Khamene’i can only dream of. In part, this results from longevity under Islamist rule, in part from difference in per capita income, which is only US$4,700 and stagnant in Iran, $10,700 and rising in Turkey.

Regime collapse in Iran is within sight and will diminish Islamism, encouraging Muslims to move toward a more modern and moderate form of their religion. The Turkish government’s greater popularity and more advanced version of Islamism gives it greater staying power that makes it the more worrisome long-term opponent. Thus, the Middle East is likely to witness a grand switch, with Iran on course to moderation and Turkey becoming the region’s supreme danger.

Many in Washington always think that Iran is on the cusp of regime change, and hopefully someday soon they’ll be right. If and when that happens though, I suspect Washington will still be caught as off-guard by Pipes’ “grand switch” as it was by the Shah’s fall in 1978.