After détente was abandoned, the U. S. president believed that the Cold War could be won by

by outspending the soviet union on weapons

Explanation:

Détente is a word that means lessening the tension in relations between nations or governments.

Détente had both economic and strategic benefits to both sides of the Cold War, driven by common interest in trying to verify the spread and proliferation of nuclear weapons. Former US President Richard Nixon and Soviet leader Leonid Brezhnev signed the treaty to limit the development of strategic weapons. Gun control has enabled both superpowers to slow the increasing increases in their swollen defense budgets. With the end of the Détente, the president of the United States believed that the Cold War could be won if the country surpassed the USSR with weapons.

A. outspending the Soviets on weapons.