I certainly wouldn’t rule it out. But I imagine the reasons are more complex than just communist agitators.
Consider the marxist Hukbalahap guerillas in the Philippines. In addition to fighting the Japanese, the Huk's terrorized anti-Japanese Filipino citizens, fought against other Filipino guerilla groups and resisted cooperation with Americans.
The Huk's, the communist Chinese and other communist groups saw themselves as leaders of post-war revolutions that would seize control of their respective governments.
As for American labor unions, they had been under heavy communist influence for years. The American communists had no desire to make the world safe for democracy. Yes, other factors were undoubtedly behind wartime labor strikes. However, red agitators had to continue letting workers know they were being exploited and oppressed by the greedy proletariat.