Why do Republicans ignore the economy when talking foreign policy?

When Republicans discuss foreign policy, something miraculous happens: America’s economic constraints disappear. Oh, sure, Rick Perry and Newt Gingrich called for slashing foreign aid, the foreign-policy equivalent of Amtrak. But when it comes to defense spending, which costs nearly 20 times as much, and the overseas commitments that have sent that spending skyrocketing since Sept. 11, you would have thought America was flush with cash. Perry and Herman Cain criticized Obama’s timetable for withdrawing troops from Afghanistan; Michele Bachmann said Obama had sent too few to begin with; Mitt Romney and Newt Gingrich ruled out negotiations with the Taliban; Romney and Rick Santorum declared themselves willing to bomb Iran.

How might war with Tehran—and the resulting disruption of the world’s oil supply—affect America’s economy? Who knows? The question never came up. What are the budgetary implications of revoking Obama’s timetable for Afghan troop withdrawal and refusing to negotiate a political settlement with the Taliban, thus closing off the only plausible avenue for ending the war? Why should the U.S. continue to spend $100 billion a year to fight a war in one of the poorest and weakest nations on earth when mammoth, prosperous nations increasingly threaten our preeminence? And how might it affect our chances of victory in Afghanistan if we go to war with Iran, its powerful neighbor to the east? Neither the moderators nor the candidates thought any of these questions important enough to even raise.