Where individual governments stand in path of Soviet purposes pressure will be brought for their removal from office. This can happen where governments directly oppose Soviet foreign policy aims (Turkey, Iran), [or] where they seal their territories off against Communist penetration (Switzerland, Portugal).

—Telegraphic Message from Moscow,
George Kennan, 1946

How was the Truman Doctrine related to this quote from the telegraph?

To contain communism, Truman declared war on the Soviets.
To contain communism, Truman promised to remove Communist citizens from Iran.
To contain communism, Truman promised to give financial aid to countries like Turkey.
To contain communism, Truman declared the Communist Party illegal in Portugal.