Senator Joseph R. Biden Jr. predicted that Barack Obama would face an international challenge in his early term by foreign enemies who want to test a young leader’s resolve as a chief executive just like John F. Kennedy did in the Cuban missile crisis in 1962. We test this argument using the directed-leader-dyad-period data for both world leaders and the US presidents between 1875 and 2001. We find that old leaders are more likely to be a target of militarized disputes, and even more so during the early term as opposed to Biden’s prediction. The impact of tenure on the likelihood of being targeted largely depends on age. We also find that old Republican US presidents are especially vulnerable to foreign challenges early in their term.