For four years after the U.S. dropped atom bombs on Hiroshima and Nagasaki to end World War II, America held a monopoly on the production of atomic weapons. During this period, debate centering on the use of nuclear bombs in future wars proliferated among government officials, scientists, religious leaders, and in the popular press. In the following article from Collier's, former Navy lieutenant commander William H. Hessler, using data from the Strategic Bombing Survey, argued that saturation bombing of urban areas during World War II, while devastating for civilians, did not achieve war aims. A future atomic war, therefore, might well destroy cities but fail to stop enemy aggression. Furthermore, with a much higher urban concentration than the Soviet Union, the U.S. had more to lose from atomic warfare. The article, while providing detailed explanations of the bomb's destructive capability, demonstrated the lack of information available regarding the long-term medical and ecological effects of radioactivity. Hessler's prose also evoked both the fascination that gadgetry of atomic warfare held for Americans of the time and the fear many felt about the risks involved in putting this technology to use. On September 24, 1949, one week after publication of this article, news that the Russians had conducted atom bomb tests shocked the nation. The following April, a National Security Council report to President Harry S. Truman advised development of a hydrogen bomb--some 1,000 times more destructive than an atom bomb--and a massive buildup of non-nuclear defenses. The subsequent outbreak of war in Korea in June 1950 justified to many a substantial increase in defense spending.

Allies during World War II, the U.S. and the Soviet Union disagreed over a number of issues after the war. These included control of Eastern Europe, division of Germany, atomic energy, international loans, and the Middle East. On February 9, 1946, Soviet premier Josef Stalin asserted that the continued existence of capitalism in the West would inevitably lead to war. Foreign Service senior diplomat George Kennan sent President Harry Truman, still forming a Soviet policy, a lengthy telegram advocating containment. Commerce Secretary Henry A. Wallace--Secretary of Agriculture (1933-1941) and Vice-President from (1941-1945)--was one of the few liberal idealists in Truman's cabinet. Wallace envisioned a "century of the common man" marked by global peace and prosperity. In the following excerpt from a letter dated July 23, 1946, Wallace urged Truman to build "mutual trust and confidence" in order to achieve "an enduring international order." Truman asked Wallace to resign. In March 1947, Truman asked Congress for money "to support free peoples who are resisting attempted subjugation by armed minorities or by outside pressures." Thus articulated, the "Truman Doctrine" of containment served as the rationale for future American Cold War foreign policy initiatives.

The interwar peace movement was arguably the largest mass movement of the 1920s and 1930s, a mobilization often overlooked in the wake of the broad popular consensus that ultimately supported the U.S. involvement in World War II. The destruction wrought in World War I (known in the 1920s and 1930s as the "Great War") and the cynical nationalist politics of the Versailles Treaty had left Americans disillusioned with the Wilsonian crusade to save the world for democracy. Senate investigations of war profiteering and shady dealings in the World War I munitions industry both expressed and deepened widespread skepticism about wars of ideals. Charles Lindbergh, popular hero of American aviation, had been speaking in support of American neutrality for some time, and allies of FDR's interventionist foreign policy sought to counter the arguments of the famous aviator. In a May 19, 1940, radio speech, Senator James F. Byrnes of South Carolina refuted Lindbergh's position, specifically rebutting a speech Lindbergh had given on military spending.

During the U.S. war in the Philippines between 1899 and 1904 (which grew out of the Spanish-American War that had erupted in 1898), ordinary American soldiers shared the nationalist zeal of their commanders and pursued the Filipino "enemy" with brutality and sometimes outright lawlessness. Racism, which flourished in the United States in this period, led American soldiers to repeatedly assert their desire "to get at the niggers." An anti-imperialist movement, which rejected annexation by the United States of former Spanish colonies like Puerto Rico and the Philippines, attempted to build opposition at home to the increasingly brutal war. Although few soldiers joined the anti-imperialist cause, their statements did sometimes provide ammunition for the opponents of annexation and war. In 1899, the Anti-Imperialist League published a pamphlet of Soldiers Letters, with the provocative subtitle: "Being Materials for a History of a War of Criminal Aggression." Historian Jim Zwick notes that the publication "was immediately controversial. Supporters of the war discounted the accounts of atrocities as the boasting of soldiers wanting to impress their friends and families at home or, because the identities of some of the writers were withheld from publication, as outright fabrications." But the brutal portrayal of the war that is found in these letters (excerpts from twenty-seven of them are included here) is supported in other accounts.

Although Cold War-era fears often focused on Communism and atomic warfare, the following 1949 editorial in the popular magazine Collier's showed concern about a broader threat to core American values posed by extremism, terrorism, and indoctrination of the country's youth. The editorial appeared beneath a photograph of a group of hooded Ku Klux Klan members, including at least three women. One of the women carried a young girl shrouded in a hood. Formally known as the Invisible Empire of the Knights of the Ku Klux Klan, the group, founded in Atlanta in October 1915, took its name and inspiration from the vigilante organization in the Reconstruction South that terrorized blacks and Republican political leaders in order to restore white supremacist governments and black economic and social subordination. While the Klan of the 19th century died out as white supremacists regained power, the virulently anti-Catholic, anti-Semitic, anti-foreigner, and anti-black 20th-century "Empire" flourished in the nativist atmosphere of the early and mid-1920s. Although the Klan declined drastically following scandals and internal battles, it revived intermittently in the following decades. As the Collier's editorialist feared, the Klan again became "a serious threat to our democracy" following successes of the modern civil rights movement, as they perpetrated acts of terrorism against African Americans and their white supporters, most notoriously in 1961 attacks on Freedom Riders in Alabama, the 1963 bombing of Birmingham's Sixteenth Street Baptist Church, that killed four young girls, and the murder of three civil rights workers in Philadelphia, Mississippi, during "Freedom Summer" in 1964. The editorial does not address cultural reasons for the Klans' persistence--historians have explored antielitism, fear of community domination by outside powers, and repugnance to modern, secularist morality as motivating factors in addition to white supremacy and nativism.

In 1916, Francisco Villa, leader of the peasant uprisings in northern Mexico, raided Columbus, New Mexico, in an attempt to expose Mexican government collaboration with the United States. President Woodrow Wilson responded by ordering an invasion of Mexico. Five years after the beginning of the Mexican Revolution, which was characterized by hope for social change as well as death, hunger, and violence, many Mexicans did not welcome further involvement by the U.S. In the following correspondence, Secretary of State Robert Lansing and President Wilson described the need to carefully frame the invasion as a defense of U.S. borders rather than interference in the Mexican Revolution. The resulting invasion, led by General John Pershing, was a total fiasco. It failed to locate Villa and increased anti-U.S. sentiment and Mexican nationalist resolve.

In 1914, during World War I, the German army passed through neutral Belgium to attack France. Afterward, many U.S. newspapers and magazines featured pro-war cartoons depicting alleged German atrocities in Belgium, particularly the killing of innocent women and children. This cartoon appeared in a 1915 edition of the weekly humor magazine Life. The slaughter in Belgium did not actually occur; but by 1915 tens of thousands of Africans had died in the Belgian Congo, victims of Belgium's ruthless exploitation of its colony's resources.

In 1910, an international consortium of banks refinanced Haiti's international debt and took control of the country's treasury. In 1914, the bank refused to issue gold payments to the Haitian government and asked the U.S. military to protect the gold reserves. On December 17, 1914, U.S. marines landed in Haiti and moved the gold to the bank's New York vaults. Eight months later, the marines again landed in Port au Prince, Haiti's capital, this time claiming the need to protect foreign lives and property. They placed Port au Prince under martial law, ruthlessly subdued armed resistance in rural areas, and began training a new Haitian militia. Charlemagne Pralte led a resistance movement. In this "call to arms" and letter to the French minister, Pralte attacked President Wilson as a hypocrite for claiming to respect the sovereignty of small nations of Europe while occupying Haiti and urged Haitians to resist the Americans. (An English translation of the letter follows the French version.)

On February 15, 1898, an explosion ripped through the American battleship Maine, anchored in Havana Harbor, sinking the ship and killing 260 sailors. Americans responded with outrage, assuming that Spain, which controlled Cuba as a colony, had sunk the ship. Many newspapers presented Spanish culpability as fact, with headlines such as "The War Ship Maine was Split in Two by an Enemy's Secret Infernal Machine." Two months later, the slogan "Remember the Maine " carried the U.S. into war with Spain. In the midst of the hysteria, few Americans paid much attention to the report issued two weeks before the U.S. entry into the war by a Court of Inquiry appointed by President McKinley. The report stated that the committee could not definitively assign blame to Spain for the sinking of the Maine. In 1911, the Maine was raised in Havana harbor and a new board of inquiry again avoided a definite conclusion. In 1976, however, in the aftermath of the Vietnam War, Admiral Hyman Rickover conducted a new investigation. Rickover, something of a maverick in the Navy, came to the conclusion that the explosion was caused by spontaneous combustion in the ship's coal bins, a problem that afflicted other ships of the period. But controversy over the sinking of the Maine continues; some recent authors have, for example, rejected Rickover's account and argued that rogue, anti-American Spanish officers used primitive mines to destroy the ship.

In 1898, the United States took control of the Caribbean island of Puerto Rico, intending to use it as a base for strategic naval operations. Most of the island's 900,000 inhabitants welcomed the end of Spanish rule. But they were divided about the U.S. presence. Some hoped links with the United States would lead to increased trade and prosperity; others wanted total independence. Some who initially welcomed the United States quickly became disillusioned. Severo Tulier, a small farmer from Vega Baja, had to sell his farm in 1899; he worked first as a field laborer, and then moved to San Juan to learn a trade. He described the conditions of life among farm workers to Henry K. Carroll, the special commissioner for the United States to Puerto Rico, who interviewed hundreds of Puerto Ricans as part of his effort to formulate U.S. policy for governing the island.

In February 1899, British novelist and poet Rudyard Kipling wrote a poem entitled "The White Man's Burden: The United States and The Philippine Islands." In this poem, Kipling urged the U.S. to take up the "burden" of empire, as had Britain and other European nations. Theodore Roosevelt, soon to become vice-president and then president, described it as "rather poor poetry, but good sense from the expansion point of view." Not everyone was as favorably impressed as Roosevelt. African Americans, among many others, objected to the notion of the "white man's burden." Among the dozens of replies to Kipling's poem was "The Black Man's Burden," written by African-American clergyman and editor H. T. Johnson and published in April 1899. A "Black Man's Burden Association" was even organized with the goal of demonstrating that mistreatment of brown people in the Philippines was an extension of the mistreatment of black Americans at home.

During the 18th century, American colonists found themselves increasingly involved in wars, often imperial ones, spiraling out of European battlefields onto the North American continent. The Seven Years War between France and Great Britain began along the western frontier and spread in 1754. New Englanders eagerly volunteered for expeditions leading to the invasion of French Canada. British and colonial forces succeeded together in capturing the great French fortress of Louisbourg in Nova Scotia in 1758. But as Massachusetts soldier Gibson Clough discovered, the British regular army looked down on the colonial militia. British concepts of discipline and social hierarchy varied significantly from colonial ones, and the war experience began to encourage colonists' conception of themselves as Americans.

Great Britain recognized the lucrative possibilities of the Atlantic slave trade long before it permanently colonized North America. By the mid-sixteenth century, British ships followed Spanish and Portuguese vessels along the West African coast and familiarized themselves with the trade between the Portuguese and Africans. John Hawkins, an admiral with royal backing, inaugurated the British slave trade with three expeditions. On his 1562 voyage, he purchased slaves from the Portuguese in West Africa and sold them to the Spanish in Hispaniola at great profit, despite Spanish prohibitions. In 1567, he seized 500 Africans in Sierre Leone and set off across the ocean, but the Spanish fleet captured him in a Mexican port and destroyed many of his ships. Although he escaped, 100 of his men were left in the Bay of Mexico; only three eventually returned England. One of those was 17-year-old Job Hortop, who wrote this narrative after 23 years in Spanish captivity.

This 1767 engraving, published in Great Britain and attributed to Benjamin Franklin, warned of the consequences of alienating the colonies through enforcement of the Stamp Act. The act was a 1765 attempt by Parliament to increase revenue from the colonies to pay for troops and colonial administration, and it required colonists to purchase stamps for many documents and printed items, such as land titles, contracts, playing cards, books, newspapers, and advertisements. Because it affected almost everyone, the act provoked widespread hostility. The cartoon depicts Britannia, surrounded by her amputated limbs marked Virginia, Pennsylvania, New York, and New England as she contemplates the decline of her empire. Franklin, who was in England representing the colonists' claims, arranged to have the image printed on cards that he distributed to members of Parliament.

U.S. marines occupied Haiti from 1915 to 1934. By 1919, Haitian Charlemagne Péralte had organized more than a thousand cacos, or armed guerrillas, to militarily oppose the marine occupation. The marines responded to the resistance with a counterinsurgency campaign that razed villages, killed thousands of Haitians, and destroyed the livelihoods of even more. In 1926 the Women's International League for Peace and Freedom (WILPF) organized a committee to look into conditions in Haiti and offer alternatives to the American policy of routinely sending in the marines.

In February 1899, British novelist and poet Rudyard Kipling wrote a poem entitled "The White Man's Burden: The United States and The Philippine Islands." In this poem, Kipling urged the U.S. to take up the "burden" of empire, as had Britain and other European nations. Theodore Roosevelt, soon to become vice-president and then president, copied the poem and sent it to his friend, Senator Henry Cabot Lodge, commenting that it was "rather poor poetry, but good sense from the expansion point of view." Not everyone was as favorably impressed. Poet Ernest Crosby penned a parody of Kipling's work, "The Real White Man's Burden," and published it in his 1902 collection of poems Swords and Plowshares. Crosby also wrote a satirical, anti-imperialist novel, Captain Jinks, Hero, that parodied the career of General Frederick Funston, the man who had captured Philippine leader Emilio Aguinaldo in 1901.

In 1912, four candidates battled to become President of the United States. Republican incumbent William Howard Taft and Democrat Woodrow Wilson, a moderate governor, represented the two major parties. Former President Theodore Roosevelt, angered over what he felt was a betrayal of his policies by Taft, his hand-picked successor, abandoned the Republican party and founded the Progressive or "Bull Moose" Party. While all four candidates appealed directly to working-class voters, whose votes would prove decisive, by far the most radical platform in the campaign was that of the Socialist Party nominee, Eugene V. Debs. Running for the fourth time, Debs called for the abolition of capitalism rather than for its reform. In this speech accepting the party's nomination he proclaimed the Socialist Party "the party of progress, the party of the future." Debs finished last in the contest, receiving 900,000 votes.

For the people of Vietnam, who were just beginning to recover from five years of ruthless economic exploitation by the Japanese, the end of World War II promised to bring eighty years of French control to a close. As the League for the Independence of Vietnam (Vietnam Doc Lap Dong Minh Hoi), better known as the Viet Minh, Vietnamese nationalists had fought against the Japanese invaders as well as the defeated French colonial authorities. With the support of rich and poor peasants, workers, businessmen, landlords, students, and intellectuals, the Viet Minh (led by Ho Chi Minh) had expanded throughout northern Vietnam where it established new local governments, redistributed some lands, and opened granaries to alleviate the famine. On September 2, 1945, Ho Chi Minh proclaimed the independent Democratic Republic of Vietnam in Hanoi's Ba Dinh square. The first lines of his speech repeated verbatim the famous second paragraph of America's 1776 Declaration of Independence.

This cover of the December, 1942, issue of Collier''s magazine commemorated the first anniversary of the Japanese attack on Pearl Harbor. The vampire-bat portrayal of Prime Minister Hideki Tojo indicates one way in which American popular media and war propaganda presented the Japanese. Unlike images of the European enemy, the Japanese were depicted as vicious animals, most often taking the form of apes or parasitic insects. The same racial stereotypes were also applied to Japanese living in America. Suspecting their loyalty, the U.S. government rounded up all Japanese Americans living on the west coast citizens and non-citizens alike and transported them to detention centers in the West. Forced to abandon their homes, jobs, and businesses, Japanese Americans remained detained in camps for the duration of the war.