Why did the Americans start selling weapons to nations at war?

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Explanation:

During the Cold War, American arms sales became part of a broader strategy to deter the Soviet Union from invading Western Europe. In the wake of the 9/11 attacks, the United States sold weapons to Afghanistan and Iraq to bolster their ability to defeat the Taliban, al Qaeda, and the Islamic State.Mar 13, 2018

answer; andrew jackson approved nullification by signing it into law,and john calhoun opposed it saying it was unconstitutional;

whats the question? im not quite understanding your question.