LONDON — Perhaps foreign policy doesn’t matter in U.S. elections. President George H.W. Bush orchestrated a peaceful unwinding of the Cold War that united Germany within the West. A Europe divided became whole and free. Hundreds of millions of people benefited. They still do. This was one of the finest hours of American diplomacy.

His reward for great achievements on the world stage was to be defeated in the 1992 election. After all, he’d raised taxes. He’d let the size of government grow. Confronted by a grocery store checkout scanner, he looked like a genteel space cadet. So he had his comeuppance from Bill Clinton, who’d got how groceries get bought.

Yes, Americans want money in their pockets that keeps food on the table: to heck with huge events across the oceans. They think foreign policy is for the birds.

Or do they? Americans have an exalted sense of their nation and its liberating mission. That self-image stops making sense if America is not engaged. The authoritative 2010 survey of American public opinion by the Chicago Council on Global Affairs found that more than 8 out of 10 Americans think it’s either “very desirable” or “somewhat desirable” for the United States to “exert strong leadership in world affairs.”