What happened at the battle of spotsylvania and the battle of cold harbor?

Why was mao zedong’s communist china ready to use military tactics against the troops of us general douglas macarthur in korea? a. mao zedong had long planned to declare war against the united states. b. us troops kept marching farther into north korea, getting closer to the chinese border. c. us president harry truman threatened to use nuclear weapons against china. d. kim il sung had requested china’s to declare war against the united states.

What principle did president truman invoke in sending u. s. troops into south korea without first asking congress to declare war?

Ineed with my dbq, i basically just need to bs it the whole way through because my apush teacher sucks but i literally don’t know how to contextualize well and i just need