Forty-seven percent is also roughly the U.S. share of global military spending. Our annual $700 billion-plus military budget exceeds the next 10 biggest military budgets combined. Much of that money buys forces needed to defend allies against threats they could afford to meet themselves. Alliances that once served the U.S. national interest have become a subsidy to rich allies. …

If Romney wants them to do more, he should suggest giving them less — a logic he appreciates in domestic contexts. The same would apply to the Japanese, South Koreans and various others we defend. Some allies, especially in Asia, might increase military spending. Others, noting less danger and bulging debts, may not. …

Those allies long ago grew rich enough to defend themselves, and the Soviet Union has been history for decades. The European Union collectively has a population and economy larger than ours. But while Americans spend about $2,700 per capita annually on the military, NATO allies average around $500.