Vladimir Putin's tacit admission that he cannot even control Moscow's airspace is the latest setback in his misbegotten war against Ukraine. Many see Donald Trump's campaign against Iran's nuclear program as a similar failure, but this view is mistaken. The two conflicts reveal important facts about the international balance of power. Russia is failing to defeat its much smaller next-door neighbor, and the United States is trying to manage the costs of compelling Iran to surrender its nuclear program. These are very different problems, and they show that Russia is falling behind.