<span>1. the cold war 2. the iron curtain 3. to oppose Soviet expansion and keep communism in check 4. the Marshall plan 5. Berlin Airlift 6. to coordinate military training for the Allies (i think) 7. to develop an Asian ally against communism 8.North Korea invaded South Korea. 9.President Truman fired him for insubordination. 10.North Korea and South Korea remained separate with a demilitarized zone along the 38th parallel. 11.Red Scare 12.a tactic of spreading fear with baseless accusations of communist activities in the United States 13.expected other nations to do their part 14.the power of the military-industrial complex
But if you're looking for specific answer, then it's the third one, (to oppose Soviet expansion and keep communism in check), Gallatin is supporting universal human rights in America, and is stating that believing that Mexicans are inferior is wrong.
One of the first things he did was declare a peace with Germany. This effectively meant that the Soviets were leaving the war and that Germany had one less things to worry about since he believed that the war was in no way helping the Russian people.