What are the reasons for the aggravation of international relations in the 1980s

What are the reasons for the aggravation of international relations in the 1980s and how was the problem of arms reduction solved during those years?

A number of revolutions that took place in Asia and Africa led to the aggravation of international relations, or rather relations between the USSR and the United States. First of all, it was the revolution in Afghanistan, which prompted the Soviet leadership to send its own troops into this country. This provoked a tough response from the United States in the form of sanctions. And the installation of medium-range missiles that were aimed at Western countries only exacerbated the situation. As a result, both states began to solve the problem of reducing armaments only in the years of perestroika, when a “new political thinking” was announced in the USSR.