Answer:
Moral hazard is encouraged by US security guarantees, in which an individual takes a greater risk because someone else bears the cost. Allies may become complacent in dealing with rivals when they are protected by the world's most powerful military.Even non-allies are susceptible to the phenomenon if they believe they have anything like a security promise from the US, as Georgia and Russia did in 2008. Using NATO to assist Ukraine today could yield similar results. Another example is Saudi Arabia's recent adventurism. Via moral hazard, alliances may cause instability among neighbors, dragging the US into wars it unintentionally encouraged. This issue would be mitigated if allies were more worried about losing US defense.