Many foreign policy strategies are supported or backed by the military power of the country employing those strategies. In the Cold War, the idea of Mutually Assured Destruction prevented direct conflicts between the Soviet Union and the United States because behind the actions of both was the threat of nuclear war.
One specific foreign policy strategy that relied on the immediate threat of military force was known as Gunboat Diplomacy or Big Stick diplomacy in the United States. The strategy relied on using immediate naval power to intimidate weaker nations into granting concessions. Widely employed by European empires in Africa and Asia in the nineteenth century, Gunboat Diplomacy became a way of projecting immediate military power into diplomatic negotiations. The United States employed this strategy when Commodore Perry forced Japan to open itself to American trade through the threat of immediate naval attack.