By any global measure, a prime minister of Singapore presides over a minuscule patch of earth and speaks for a tiny fraction of the world’s population. Yet notwithstanding the city-state’s small size—or maybe because of it—its prime ministers often have a keener grasp of American interests than Americans do.

So it’s no surprise that Lee Hsien Loong, Singapore’s current prime minister, would come right to the point in a meeting with The Wall Street Journal editorial board. When asked for his take on the Obama administration’s...