Why did it increase its involvement into the 1970s?

What important cold war symbol was destroyed in Germany in 1989? Was there a solution to ending the Vietnam War? How many Draftees vs Enlisted for World War 2? What was the outcome of the battle between the monitor and the Virginia? What was the northern army called during the civil war? What did soldiers in training elect? Who were the yankies? Who said If slavery must go by blood and war let war come? Southern weapons in civil war? What was the first phase of the battle Antietam about? What roles did ideology and nuclear weapons play in the development of the cold war tensions between the superpowers? Does Lt Emmett die in U-571? How were the efforts of General Grant and Sherman at the end of the war similar and different? What are Anti war protesters? How did tanks change the face of battle in World War I? What treaty helped diffuse tensions between the USSR and the US? What the terms of the peace treaty? What was Arthur Harris's nickname? Why did the assassination of czar Nicholas II take Russia out of the war? How did the union's strategy differ from that of the confederacy?