"Peace through strength" is a phrase that suggests that military power can help preserve peace. It has been used by many leaders from Roman Emperor Hadrian in the second century AD to former US President Ronald Reagan in the 1980s. The concept has long been associated with realpolitik. The idea has critics, with Andrew Bacevich stating, Peace through strength' easily enough becomes 'peace through war.
The phrase and the concept date to ancient times. Roman Emperor Hadrian (AD 76–138) is said to have sought "peace through strength or, failing that, peace through threat." Hadrian's Wall was a symbol of the policy.
The first US president, George Washington, enunciated a policy of peace through strength in his fifth annual message to Congress, the 1793 State of the Union Address. He said:
There is a rank due to the United States among nations which will be withheld, if not absolutely lost, by the reputation of weakness. If we desire to avoid insult, we must be able to repel it; if we desire to secure peace, one of the most powerful instruments of our rising prosperity, it must be known that we are at all times ready for war.
In Federalist No. 24, Alexander Hamilton argued for peace through strength by stating that strong garrisons in the west and a navy in the east would protect the Union from the threat of Britain and Spain.
Peace Through Strength is the motto of the Eighth Air Force, established in 1944.
Peace Through Strength (1952) is the title of a book about a defense plan by Bernard Baruch, a World War II adviser to US President Franklin D. Roosevelt, published by Farrar, Straus and Young. During the 1964 presidential campaign in the United States, the Republican Party spent about $5 million on "Peace through Strength" TV spots. For supporters of the MX missile in the 1970s, the missile symbolized "peace through strength."
In 1980, Ronald Reagan used the phrase during his election challenge against Jimmy Carter by accusing the incumbent of weak, vacillating leadership that invited enemies to attack the United States and its allies.