When President Donald Trump visits Beijing this week, he should have the satisfaction of knowing that time, in the long run, is on America’s side. Unfortunately, that’s also the problem. That’s the opposite of a conventional wisdom that holds that the United States is a fumbling status quo power, akin to Britain in the waning years of its empire, squandering its strength in sideshow wars (South Africa then; Iran now) while failing to grapple with its principal strategic and economic competitor (Germany then; China now). It’s this same conventional wisdom that has been telling us that, any year now, China will overtake the United States as the world’s largest economy. But China’s economy most likely will never overtake America’s, just as past would-be contenders — whether they were the Soviet Union, Japan or the European Union — all fell short. Why? Because history shows that the most productive national assets are political freedom and open markets — the freer, more open and more competitive, the better.…