why was the cold war called by this name?

The first two peacekeeping operations deployed by the UN were the UN Truce Supervision Organization (UNTSO) and the UN Military Observer Group in India and Pakistan (UNMOGIP). Those missions consisted of unarmed military observers and lightly armed troops with primarily monitoring, reporting and confidence-building roles. Peacekeeping was primarily limited to maintaining ceasefires and stabilizing situations on the ground, providing crucial support for political efforts to resolve conflict by peaceful means. UN Peacekeeping was born at a time when Cold War rivalries frequently paralyzed the Security Council. More than 3,000 UN peacekeepers from some 120 countries have died while serving under the UN flag.

Over the years, hundreds of thousands of military personnel, as well as tens of thousands of UN police and other civilians from more than 120 countries have participated in UN peacekeeping operations. Since then, more than 70 peacekeeping operations have been deployed by the UN. The mission's role was to monitor the Armistice Agreement between Israel and its Arab neighbours – an operation which became known as the United Nations Truce Supervision Organization (UNTSO).

Why was the cold war called by this name?