Many news outlets refer to Saudi Arabia's role in Yemen as fighting as America's proxy.
"The result is that Yemen has been isolated from the world and left to die. More than 80 percent of its population—21.1 million people—is in need of aid. Thirteen million are at risk from starvation and 9.4 million are imperiled by thirst." (source)
Most famously, in 1953, the CIA overthrew the democratically elected government of Iran led by Prime Minister Mohammad Mossadegh who had attempted to nationalize Iran's petroleum industry for the benefit of his own country-men.
The Guatemalan Revolution of 1944-54 had overthrown the US backed dictator Jorge Ubico and brought a democratically elected government to power. The government began an ambitious agrarian reform program attempting to grant land to millions of landless peasants. This program threatened the land holdings of the United Fruit Company, who lobbied for a coup by portraying these reforms as communist. The CIA engineered the overthrow of the democratically elected government of Jacobo Árbenz, and installed the military dictator Carlos Castillo Armas. A decades long civil war ensued in which some 200,000 people were killed, mostly by the US backed military.
The CIA backed a coup against President Ngô Đình Diệm of South Vietnam. The United States gave secret assurances that the U.S. would not interfere. An operative of the CIA provided a group of South Vietnamese generals with $40,000 to carry out the coup with the promise that US forces would make no attempt to protect Diệm.
Upon learning of Diệm's ouster and death, Hồ Chí Minh reportedly said, "I can scarcely believe the Americans would be so stupid." Well, we were so stupid and the full story can be read in the history books or in Wikipedia.
In the most recent attacks on those who attempt to tell the truth we have imprisoned several honorable citizens of this nation. People who simply saw wrong-doing, felt an obligation to do the 'right thing' and believed they should tell the truth have themselves ended up being prosecuted by the legal system and going to prison. Our national motto should be, 'if you see the crime, see yourself doing time!'