Respuesta :
"Britain's inability to assist governments in Greece and Turkey" is the one event among the choices given in the question that triggered the United States to issue the Truman Doctrine. The correct option among all the options that are given in the question is the second option. I hope the answer has helped you.
I believe the answer is: Britain's inability to assist governments in Greece and Turkey
According to Truman doctrine, United States shall provide economic and military assistance to other countries to battle soviet union influence during the cold war.
This doctrine was created because Truman Argued that if Turkey and Greece was not given military assistance, they would most likely fall to soviet union's ideology.