Zinn makes the argument that it wasn't just Soviet expansion that worried the US. What does he say was worrying about China, Korea, Indochina, and the Philippines?

The Unites States worried about China, Korea, Indochina and the Philippines because they were threatening the U. S. A. through local Communist movements. These countries opposed the foreign policy and the imperialistic attitude of the colonizers.

Explanation:

Harry Truman was the 33rd President of the U. S. A. Under his governance, he wanted to achieve "national unity" among the nations when it comes to militarization of budget. He made made an executive order that supported this and included anti-Communism laws.

Armed attacks were repelled in cases where nations opposed to the "rule of force." This was the reason why many Asians such as Koreans were killed during the Korean war.

So, this clearly shows that the U. S. A was not only threatened by the Soviet expansion but it also worried about other Asian countries. Many of the nations were demanding "independence," thus paving way to revolutionary movements.