The practice of backing up diplomatic efforts with a visible show of military might. A nation using gunboat diplomacy is making use of implicit military threats to achieve its policy objectives.
A gunboat was a relatively small ship which could navigate through shallow waters; easy to maneuver, the boats were fitted with heavy weapons.
The most obvious examples of gunboat diplomacy come from the 19th and early 20th century. In 1854, Japan and the United States signed the Treaty of Kanagawa, opening up trade between the two nations for the first time in 200 years. The agreement came about after Commodore Matthew Perry led a naval squadron to Tokyo Bay. As the US State Department has put it,
“Perry arrived in Japanese waters with a small squadron of U.S. Navy ships, because he and others believed the only way to convince the Japanese to accept western trade was to display a willingness to use its advanced firepower.”
President Theodore Roosevelt is often credited with expanding America’s use of gunboat diplomacy. Roosevelt famously said that his diplomatic motto was to “speak softly and carry a big stick,” which, he said, meant that the nation had to be ready to back up words with force. Roosevelt built up the US military might and routinely made a practice of showing off the nation’s might as a way to pre-empt potential challenges.
In order to show off America’s naval power, Roosevelt sent a naval fleet around the world, on a tour which lasted 14 months. The fleet was known as the Great White Fleet (its ships were painted white, instead of the usual gray), and consisted of 16 battleships manned by 14,000 sailors. The fleet set out on December 16, 190y and concluded its journey on February 22, 1909. The Great White Fleet called in Hawaii, New Zealand, Australia, Japan, and Egypt, before continuing on to Italy and Gibralter. (Along the way, the sailors provided assistance to victims of an earthquake in Sicily.)
In theory, the era of gunboat diplomacy ended with Franklin Roosevelt’s first term. FDR announced his “good neighbor” policy in his first inaugural address, vowing that “in the field of world policy I would dedicate this nation to the policy of the good neighbor—the neighbor who resolutely respects himself and, because he does so, respects the rights of others.”
In reality, of course, the US has never completely abandoned the show of force. In 2011, the New York Times summed up the Obama administration’s activities in Asia:
“the Obama administration has been an active practitioner of gunboat diplomacy, a term that refers to achieving foreign-policy objectives through vivid displays of naval might. Last fall, Mr. Obama sent the aircraft carrier George Washington to the Yellow Sea for joint exercises with South Korea, sending a message to both North Korea and its key backer, China. The move echoed the Clinton administration’s decision in 1996 to send the Seventh Fleet to warn China against attacking Taiwan.”
More recently, the Heritage Foundation noted approvingly that the Trump Administration was using gunboat diplomacy in Iran:
“The U.S. is not the world’s policeman or its babysitter, but it doesn’t want to be blindsided by bad actors who think Washington is so preoccupied elsewhere that they can take advantage of the situation. Thus, the U.S. has to demonstrate it is present and capable of acting where it needs to.
The deployment to the Gulf will be a deterrent to conflict because it shows the world that the U.S. will act wherever necessary to protect its vital interests. Testing the U.S. is the last step any adversary should want to take, Tehran included.”