manage the colonial troops fighting the Revolutionary War
Firing the joint chiefs of staff would look bad for Kennedy because it would make it appear to the public that the administration is struggling/weak. Anytime there are scandals or issues in which the president does not get along with his colleagues, it is seen as a sign of weakness. During Kennedy's presidency, the last thing the United States government wanted was to appear weak. This is because the US was in constant competition with the Soviet Union for international power and influence.
The Sherman Antitrust act was created for that purpose, but it was also supported by the Clayton Antitrust Act which came later on. Roosevelt was known as "Teddy the Trust-Buster" for his strict enforcement of these acts.
There are many different trains of thought that lead Americans to their own mindset about the aid of Middle Eastern independence.
Generally speaking, there are many people who believe that the United States should be the Police of the world or the hero of smaller countries and help them since they have the power to do so.
Others believe that the United States has no rights of interfering in foreign affairs and should mind their own business.
There are those who just don't agree with the idea of sending kids to die for other countries as well, no matter why.