When it comes to U.S. foreign policy, Americans must sometimes feel like Goldilocks in the three bears’ house. The porridge that was President George W. Bush’s “freedom agenda”—promising democracy for everyone from Karachi to Casablanca—was too hot. The mush that has been President Barack Obama’s foreign policy—heavy on rhetoric about resets, pivots and engagement but weak in execution and deeply ambivalent about the uses of U.S. power—is too cold.

What we need instead, as the fairy tale has it, is a foreign policy that is...