Unfortunately, the only leverage US weapons sales provide is the type that recipient countries use to receive ever more arms, despite their risks. According to academic studies, foreign aid for influence and arms for influence attempts are unsuccessful.
The Cato Institute’s arms sales risk index project sees similar results. For example, Saudi Arabia has the largest recipient of American-made weapons since 2009. Riyadh has used these weapons against US interests to continue ravaging Yemen and an “anti-corruption purge” to crack down on those fighting government corruption.
Former President Donald Trump ironically understood the follies of arms providing influence. Congress attempted to cancel sales to Saudi Arabia after the murder of Jamal Khashoggi. But Trump argued that “we would be punishing ourselves” by canceling these weapons transfers. He believed that stopping the weapons flow would hurt the United States more than the Saudis, and as a result, these sales would continue.