Truman's decision to enter the Korean War without congressional authorization marked a major shift in presidential war powers

Presidents have often used military force without formal declarations of war

Although the Constitution grants Congress the power to declare war, American presidents have repeatedly ordered military action without formal declarations. These precedents have expanded executive authority in national security beyond what the framers likely envisioned.

Youngstown Sheet & Tube Co. v. Sawyer established the framework courts use to evaluate presidential war powers

When Truman seized US steel mills during the Korean War, the Supreme Court ruled that he had overstepped his authority. Justice Jackson's concurring opinion held that presidential power is strongest when Congress authorizes action, uncertain when Congress is silent, and weakest when Congress explicitly refuses authorization.

The War Powers Act may have ironically given presidents more discretion to engage in hostilities, not less

In this wide-ranging podcast on Congress's power to declare war, scholar Gary Schmitt argues that the War Powers Act, ironically, gave presidents a legal framework for initiating hostilities, creating a 60-day window for unilateral action that hadn't existed before.

The US never formally declared war in Vietnam

Instead of formally declaring war, Congress passed the Gulf of Tonkin Resolution in 1964, granting President Johnson broad authority to use military force. The resolution became the legal basis for escalating US involvement without an official declaration of war.

The War Powers Act of 1973 was passed over Nixon's veto to limit the president's ability to wage war unilaterally

Passed in the aftermath of the Vietnam War, the War Powers Resolution requires the president to notify Congress within 48 hours of deploying forces and to end military operations within 60 days without congressional approval. Nixon vetoed the bill, arguing it was unconstitutional, but Congress overrode his veto.

The Prize Cases established that the president can respond to an attack without waiting for Congress to act

When Lincoln blockaded Confederate ports at the start of the Civil War without congressional authorization, the Supreme Court upheld his actions, ruling that a president does not initiate war by responding to an attack and need not wait for Congress when the nation is already under threat.

The president has the sole authority to call for a nuclear strike

Under current US policy, the president alone can order the use of atomic weapons at any time without requiring prior approval from Congress—a power rooted in the president's role as commander in chief.

A digital archive of the Korean War

The Korean War largely shaped the evolution of the Cold War in Asia. Explore the Wilson Center’s digital collection of primary sources—including essays, profiles, popular documents, and a timeline—to learn about the Korean War. In 1945, the...

President Harry Truman appointed Roosevelt as one of the first US delegates to the United Nations

After FDR's death in 1945, Roosevelt joined the delegation to the newly established United Nations. She was the only woman among the General Assembly delegates and was unanimously elected to chair the UN Commission on Human Rights.

In the 1930s, Congress nearly passed a constitutional amendment requiring a national vote before declaring war

The Ludlow Amendment, proposed amid rising isolationism after World War I, would have required a national referendum before Congress could declare war, except in cases of direct attack. It was defeated 209 to 188 in 1938 after Roosevelt lobbied against it.

US defense spending peaked during the Korean War at 13% of GDP

In 1953, during the Korean War, US defense spending reached 13.58% of GDP—more than three times today’s level. That peak marked the most militarized moment of the Cold War, and spending has never returned to that level since.

How two US Presidents defined WWII and its aftermath

The National WWII Museum’s “To the Best of My Ability” podcast series delves into how Presidents Franklin D. Roosevelt and Harry S. Truman steered the US through World War Two.

The Truman Doctrine marked the start of US containment strategy

Introduced in 1947, the Truman Doctrine pledged US support for nations resisting communism—starting with Greece and Turkey—and launched the containment policy that defined early Cold War strategy.

Hitler declared war on the United States four days after Pearl Harbor

Despite having no treaty obligation to join Japan’s fight, Hitler declared war on the US on Dec. 11, 1941. The move pulled America into the European theater and is widely seen as one of Hitler’s most strategic blunders.

President Polk deliberately provoked war with Mexico

After Mexico refused to sell California and New Mexico, President James K. Polk ordered US troops into disputed territory between the Nueces River and the Rio Grande—knowing it would likely spark a conflict. When fighting broke out, he used it to justify declaring war.

The 1956 Suez crisis was one of the earliest tests of the rules-based order

When Britain, France, and Israel secretly invaded Egypt, the Eisenhower administration supported UN resolutions condemning the invasion and called for a ceasefire—publicly criticizing its closest allies to uphold the principle that force should not be used to resolve international disputes.

The threat of nuclear annihilation reshaped global diplomacy

The first use of atomic weapons introduced the possibility of a war with no survivors. This article examines how nuclear fear shaped Cold War diplomacy and continues to influence international relations today.

Theodore Roosevelt is considered by many to be the "first modern president"

Roosevelt transformed the presidency by expanding executive power beyond conventional norms, arguing that the president could act in the national interest unless expressly forbidden to do so. His energetic leadership, media use, and policy activism expanded the office's role and prestige.

Television transformed the State of the Union, beginning with Harry Truman

In 1947, President Truman delivered the first televised State of the Union address, marking the address's shift into the visual age and expanding the president's reach beyond radio to a national TV audience.

The US and the USSR backed opposing sides in dozens of proxy wars during the Cold War

To avoid direct confrontation, the superpowers supported rival factions in conflicts around the world—including in Korea, Vietnam, Angola, and Afghanistan.

'Keep working on a plan. Make no little plans. Make the biggest one you can think of, and spend the rest of your life carrying it out.'

- President Harry Truman (1884-1972)

Ulysses S. Grant's leadership proved decisive in victory—and shaped postwar America

Elevated to general-in-chief in 1864, Ulysses S. Grant unified the Union strategy and forced a Confederate surrender at Appomattox. Elected president in 1868, he worked to enforce Reconstruction laws and protect the civil rights of freed African Americans.

Decisions at NATO are by consensus and must be unanimous

There are two strategic commands in NATO: one in Europe (Supreme Allied Headquarters Command Europe) and another in Norfolk, Virginia (Allied Command Transformation). The alliance is headed by both a military officer and a civilian leader.

North Korea's Kim Jong Un travels in a train with a helicopter and antiaircraft guns

The train, known as the Taeyangho (or "sun"), is a moving fortress, the country's equivalent of Air Force One. Its windows are bulletproof, exteriors built to withstand explosions, and heavy with armaments. Kim claims the train helps signal closeness to the people.

‘Dispatches’ by Michael Herr pushed the boundaries of war journalism

Straying from the typical protocol of reporting casualties and soldiers' whereabouts, Herr reported about the Vietnam War from the field while emphasizing its surreal and tragic nature. His account detailed the experiences of soldiers, while also expressing uncertainty about the meaning of the war.

In 2025, four executives from large tech companies were given positions in the US Army Reserves—including Palantir Chief Technology Officer Shyam Sankar, which reinforced Palantir's ties with the US military and its role as a leading defense partner.

The United States has had a tumultuous relationship with Cuba since its 1959 revolution, highlighted by a nuclear crisis and a decades-long trade embargo.

Long before Major League Baseball began allowing instant replay for balls and strikes, an umpire reluctantly used the technology to determine whether a hit was a home run, a move that inadvertently ushered in a new era for the sport.

Abraham Lincoln was almost assassinated weeks before his inauguration as he traveled from Illinois to DC through Baltimore in 1861; it took two independent claims for Lincoln to be convinced the threat was real

The US Constitution is widely regarded as the longest-standing written national constitution still in force—see how it has influenced rights worldwide.

'Grand Canyon of the Yellowstone,' a work by American painter Thomas Moran, inspired Congress to establish Yellowstone National Park.

Before humans, the Soviet Union and the United States sent animals—including apes, dogs, and cats—to space during the Space Race.

Jimmy Carter signed a 1978 bill that legalized home brewing, a move credited with kick-starting the craft beer industry.

Before writing 'Walden,' transcendentalist Henry David Thoreau nearly burned down his hometown with a campfire that grew out of control.

The Russia-Ukraine conflict is the largest ground war in Europe since World War II in terms of casualties, forces mobilized, and displacement of civilians.

Sunflowers have long been a symbol of nuclear disarmament because they can extract large amounts of radioactive cesium from soil.

The story of Dollree Mapp, whose legal challenge over her 1957 conviction for possessing "obscene material" led to a major strengthening of the Fourth Amendment

American dance legend Martha Graham, sometimes called 'the Picasso of dance,' refused to perform at the 1936 Olympics in Berlin and conceived the piece 'Chronicle' in response to the experience.

The identity of the Tank Man in the iconic photo from the 1989 Tiananmen Square protests remains unknown and was possibly killed.

Explore an interactive map of battles from the American Revolution, along with detailed summaries of each engagement

The US first hosted the World Cup in 1994, a tournament that lives in soccer infamy for its poor planning and the murder of Colombian player Andres Escobar, who'd accidentally scored on his own net.

In 1984, Operation Smash Hit intentionally crashed a 239-ton train into a nuclear waste canister at 100 miles per hour to prove the canister's safety, which remained completely intact and lost just 0.29 of its 100 pounds of pressure.

Chaos theory—informally known as the butterfly effect—is the reason why weather forecasts are presented with probabilities rather than certainties.

In 1945, Surrealist artist Salvador Dalí and legendary animator Walt Disney began collaborating on a short film that was not completed until 2003, years after both men had died.

The Ramones' 'Pet Sematary,' the theme song for the Stephen King novel of the same name, was written while the band was admiring the writer's collection of horror memorabilia.

Warren Buffett's former professor Benjamin Graham is known as the 'father of value investing,' a strategy in which investors seek to buy stocks trading below their intrinsic worth.

An initial public offering or 'IPO' is the process of a private company becoming public by putting shares of the company on the stock market for purchase.

Fireworks-related ER visits are on the rise—in 2024, they increased by 52% as compared to the prior year.

Hookworm infection, though risky, may help fight certain autoimmune conditions by tamping down the immune system's inflammatory response.