George H. W. Bush was president during the gulf war.
Which gulf war? There were three of them in the 20th and 21st centuries.
President Reagan during the Iraq-Iran Persian Gulf War; Truman for the Korean War; Eisenhower, Kennedy, Johnson, Nixon, and Ford for Vietnam.
George H. W. Bush was president during the first war with Iraq.
There are two ways to approach this question. One is that the "who" refers to a person. In that case, a synonym for the Gulf war could be the President Bush war. If the word "who" was meant to be "what" then the Gulf War could have the synonym of the "Desert War".
George H Bush
Reagan was president during the Iran-Iraq War in the Persian Gulf (1980-1988).
Persian Gulf War
President George H.W. Bush was the President during the Gulf War. President George W. Bush was the President during the Iraq War.
George H. W. Bush
President Carter and Reagan.
President Bush