The U.S. must increase defense spending to Cold War levels if it expects to contend with international threats posed by a malign alliance of Russia, China, Iran and North Korea that could lead to a global war, according to a commission appointed by Congress. On Wednesday, former California Rep. Jane Harman and Ambassador Eric Edelman, the chair and vice chair of the Commission on the National Defense Strategy, told lawmakers that the U.S. is facing its most severe threats in decades. The U.S. last fought a global conflict in World War II nearly 80 years ago and isn’t prepared for...