The United States has often played the role of peacemaker in the world. It has not always been successful, but it has tried to play this role. In the 1990s, the US played peacemaker in a number of places in the world.
To begin with, it is possible to argue that the main war the US was involved in in the 1990s was an attempt to keep the peace. This was the Persian Gulf War in which the US headed a coalition that went to war with Iraq to eject Iraq from Kuwait. This can be seen as peacekeeping as it was meant to reverse the unprovoked invasion of Kuwait and to prevent a potential attack on Saudi Arabia.
The US then tried to keep the peace or bring peace about in many other places. For example, President Clinton was deeply involved in trying to bring about a peaceful resolution to the conflict between the Israelis and the Palestinians. He might have succeeded had Yitzhak Rabin not been assassinated. The US was also deeply involved in trying to bring peace to the former Yugoslavia. It was Clinton’s administration that brokered the Dayton Accords that ended the war in Bosnia.
While the US was not always successful, it generally did try to act as a peacekeeper in this decade.