“The Constitution has never greatly bothered any wartime president,” wrote Francis Biddle, F.D.R.’s attorney general during World War II. Biddle was writing about Roosevelt’s shameful 1942 decision to evacuate Japanese-Americans from the Pacific Coast and place them in internment camps. But Biddle’s comment applies to all presidents in times of crisis. National survival or, perhaps more accurately, the president’s perception of national survival always takes precedence. George W. Bush has been no exception.

In 1798, during the undeclared war against France, President John Adams supported passage of the Alien and Sedition Acts, which criminalized political dissent and gave the president a free hand to deport any noncitizen he deemed “dangerous to the peace and safety of the United States.”

Ten years later, President Thomas Jefferson sought to enforce the Embargo Act, which prohibited trade with Great Britain, by charging those who violated it with treason – an egregious example of executive overreach that the federal courts quickly rejected.

Andrew Jackson’s contempt for the treaty rights of the Cherokee Nation is a familiar story. Less well-known is Jackson’s attempt to halt the distribution of abolitionist literature in the South by censoring the mail.

Abraham Lincoln suspended the writ of habeas corpus during the Civil War, and in several states he ordered the trial of civilians by military tribunals. Although Congress explicitly authorized Lincoln to suspend the writ, it was a draconian measure that the president believed essential to preserve the Union. “Are all the laws, but one, to go unexecuted, and the government itself go to pieces, lest that one be violated?” he asked.

Unlike Adams, Jefferson and Jackson, Lincoln was responding to an armed insurrection that threatened the nation’s survival. Most historians have judged his action as commensurate with the threat.

For more than 100 years, from the expiration of the Sedition Act of 1798 until America’s entry into World War I, the United States had no federal legislation banning rebellious expression. The War of 1812, the Mexican War, the Civil War and the Spanish-American War all were fought without criminalizing the right of dissent.

It was Woodrow Wilson, shortly after his re-election in 1916 but well before America’s entry into World War I, who sought legislation to suppress disloyalty. Wilson requested that Congress give the president absolute authority to censor the press in the event of war, to make it a federal crime to promote the success of America’s enemies and to close the mail to any material deemed “of a treasonable or anarchistic character.” Wilson insisted that the power he requested was “absolutely necessary to the public safety.” After America entered the war, Congress passed the Espionage Act of 1917, which incorporated much of what Wilson asked for but not the authority to censor the press.

F.D.R. may be guilty of the most extreme disregard for civil liberty, although his action was endorsed by Congress and later upheld in two landmark Supreme Court decisions. Unlike Wilson and Adams, F.D.R. had no interest in launching a wartime crusade to promote ideological conformity. But he had been blindsided by the Japanese attack on Pearl Harbor, and he was unwilling to second-guess the War Department when it urged action in the interest of military security. The 1942 relocation of Japanese-Americans from their homes on the West Coast was, in Roosevelt’s view, simply another act of wartime necessity dictated by the risk to America’s defenses.

But there was little justification for the action. Adm. Harold Stark, the chief of naval operations, and Gen. Mark Clark, the Army’s deputy chief of staff, had testified before Congress that the Pacific Coast was in no danger of invasion, and the possibility of Japanese-immigrant-inspired sabotage was no greater than that which might arise from German or Italian immigrants elsewhere in the country.

The initial agitation to remove the Japanese came from California civilians, and was tainted by long-standing racism and greed. The clamor was magnified by the state’s political leaders, including Earl Warren, then California’s attorney general, and was transmitted to Washington by Lt. Gen. John DeWitt, the overall Army commander on the West Coast.

When De Witt’s request arrived at the War Department, the Army general staff vigorously opposed the action. But the Pentagon’s civilian leadership, Secretary Henry L. Stimson and Assistant Secretary John J. McCloy, were convinced of the military necessity and transmitted that view to F.D.R. Roosevelt gave the matter too little attention; if Stimson and McCloy recommended that the Japanese be evacuated, he was not going to dispute them. On Feb. 19, 1942, Roosevelt signed the executive order that they had prepared, authorizing the forcible evacuation of people of Japanese ancestry from a designated war zone along the Pacific Coast.

By presidential directive, 120,000 Japanese residents, 80,000 of whom were American citizens by birth, were taken from their homes, farms and businesses and interned at relocation sites far inland. Roosevelt showed little remorse. In March of 1942, when Henry Morgenthau Jr., the treasury secretary, told F.D.R. about the financial losses the Japanese had suffered, the president said he was “not concerned about that.” History has judged Roosevelt harshly. There is little question that he had the authority to issue the order. Whether he should have done so is another matter.

In the Korean conflict, President Harry Truman stretched his commander-in-chief power to seize and operate the nation’s steel mills. During the Vietnam War, President Richard Nixon sought to prevent The New York Times and The Washington Post from publishing the Pentagon Papers, secret documents pertaining to American military strategy that Daniel Ellsberg had stolen from the Defense Department. In neither case was national survival at risk, and in both cases the Supreme Court struck down the president’s action.

There is an old legal maxim that in time of war the laws are silent: Inter arma silent leges. But the crucial issue is the extent to which the nation is threatened. In the cases of Lincoln and Roosevelt, the survival of the United States hung in the balance. A president will be forgiven by his contemporaries, though not necessarily by later generations, for acting outside the law when that is the case. As more than one Supreme Court justice has said, the Constitution is not a suicide pact. When national survival is not threatened, however, it is essential for a chief executive to resist an unwarranted enlargement of his powers.

A national security concern does not become a war simply because it is baptized as such. President George W. Bush’s questionable use of the metaphor “war on terror” to justify indefinite detention of suspects, warrantless eavesdropping and spying on the reading habits of citizens could invite from historians even more opprobrium than they have cast on the repressive actions taken by other presidents when the survival of the United States was at risk.