During the 1990-1991 Gulf War, Japan famously did not get directly involved on the ground.
Constrained by its pacifist Constitution, the country opted instead to engage in economic sanctions against Iraq while contributing close to $16 billion to the war and reconstruction effort. Despite being one of the largest financial contributors, Japan received little international recognition for its efforts, even being criticized by some for its so-called checkbook diplomacy.
This experience was subsequently seen as a foreign policy failure by Japanese policymakers. They responded by passing a law in 1992 that allowed the Japan Self-Defense Forces to take part in U.N. peacekeeping operations — paving a way for more active foreign policy.