After the collapse of the Soviet Union, the United States was once again free to launch direct military invasions. When it found a leader it didn’t like — such as Saddam Hussein or Muammar Qaddafi — it deposed him not through covert action, but by returning to the approach it had used before World War II: the force of arms. Covert efforts to overthrow governments have hardly ceased, as any Iranian or Venezuelan could attest. The era when covert action was America’s principal weapon in world affairs, however, is over. That makes this a good time to look back.