The world is running out of soldiers

A war between the United States and China would involve the kind of military manpower the world hasn’t seen in decades. As a point of contrast, around 156,000 troops landed on the beaches of France during the Normandy invasion in 1944, which was commemorated by world leaders earlier this month. Some experts estimate that if China were to try to invade Taiwan — the most likely flashpoint for a superpower confrontation — it might need as many as a million. If the US were to defend the island, according to some estimates it might suffer as many...