Deliveries of American weapons to Ukraine lead to an aggravation of tension between Russia and the United States. The uncontrolled use of defense products by Ukrainians threatens not only with the curtailment of previous agreements, but also with a high risk of a collision between the world’s leading nuclear powers. The U.S. Congress could require increased accountability for the use of weapons through the use of arms export control laws (H.R.13680, Leahy Law, S.3394). Nevertheless, under the conditions of polarization, the parties of Republicans and Democrats cannot agree even on issues of strategic importance. As shown in the article, from the very beginning of the conflict in the South-East of Ukraine in 2014, both parties have been actively supporting the supply of lethal weapons to Kyiv. Politicians reacted negatively to any attempt to reduce military aid or slow down its export. For this reason, they repeatedly made mutual accusations, accusing their colleagues of unwillingness to provide military support to Ukraine. The most striking episode of the impact of polarization on the problem of arms exports was the scandal with the alleged pressure of the U.S. President D. Trump on the Ukrainian leader V. A. Zelenskii, when the head of the White House was suspected of trying to diminish the former Vice-President J. Biden. Despite the failed impeachment attempt by the Democrats, D. Trump was forced to resume the supply of lethal weapons to Kyiv. The influence of polarization continued later, when conservative Republicans in the House of Representatives and the Senate spoke out against arms sales. In the article, it is shown that despite the attempts of individual politicians, the United States is unlikely to be able to increase control over the supply of weapons, since such a step will be perceived critically by the opposite side.