Answer:
(1) Persian Gulf Conflict - American intervention led to the survival of Kuwait as an independent country. Without the U.S., Kuwait would have probably succumbed to Iraqi aggression since Iraq is a much larger and powerful country. This intervention also weakened the regime of Saddam Hussein, the former dictator of Iraq.
(2) the invasion of Afghanistan - American intervention resulted in the removal of the Taliban from power, and the installment of a U.S. friendly government that still rules the country, officially. However, the Taliban still have de facto control over vast areas of the country.
(3) the invasion of Iraq. - American intervention resulted in the removal from power and capture of Saddam Hussein, who would be excecuted years later. However, this invasion was also a complicated matter that made the country more unstable, worsened relations between sunni muslims, shia muslims, and kurds, and paved the way for the emergence of ISIS.