Diplomacy

Diplomacy comprises spoken or written communication by representatives of state or governmental institutions intended to influence events in the international system. Diplomacy is typically undertaken and carried out by diplomats, such as ambassadors, although high-level diplomacy may be conducted by rulers directly.
Diplomacy is the main tool of foreign policy which represents the broader goals and strategies that guide a state's interactions with the rest of the world. International treaties, agreements, alliances, and other manifestations of international relations are usually the result of diplomatic negotiations and processes.
The two primary tools of diplomacy include carrots, such as marriage between rulers; sticks, mainly the threat of war.