A belief that the United States is safest and most prosperous when it leaves others alone and insists that others leave it alone;
Isolationism refers to America's longstanding unwillingness to become involved in European alliances and wars. Isolationists held the view that America's perspective on the world was different from that of European societies and that America could advance the cause of freedom and democracy by means other than war.
The colonial period
The isolationist perspective dates to colonial days. The colonies were populated by many people who had fled from Europe, where there was religious persecution, economic privation and war. Their new homeland was looked upon as a place to make things better than the old ways. The sheer distance and rigors of the voyage from Europe tended to accentuate the remoteness of the New World from the Old. The roots of isolationism were well established years before independence, notwithstanding the alliance with France during the War for Independence. George Washington warned in his Farewell Address against involvement in European affairs.
World War I
Wilson and World War I
In the summer of 1914 all Europe was plunged into war. Wilson called upon the United States to be neutral "even in spirit," but few Americans were able to remain impartial. For two years the president made every effort to avoid war. Even after the unarmed British liner Lusitania was sunk by a German submarine with a loss of almost 1,200 lives including 124 Americans, he argued: "There is such a thing as a man being too proud to fight."
In 1916 he was reelected. After the election Wilson tried to end the war by active mediation. The Germans, however, resumed unrestricted submarine warfare. On April 2, 1917, the president asked Congress for a declaration of war. Before a joint session of the two houses he read the solemn words, "The present German submarine warfare against commerce is a warfare against mankind. It is a war against all...