National Emergencies

President Obama's Oct. 24 decision to officially declare the H1N1 swine-flu virus a national emergency came with a speedy caveat: Don't panic. The declaration was just a formality, the White House explained, a way to allow hospitals to circumvent unnecessary restrictions in order to bring about quicker, more effective swine-flu treatment. Yes, H1N1 cases are on the rise — 46 of the 50 states are experiencing widespread influenza activity, according to the U.S. Centers for Disease Control and Prevention — but it's hardly a horrific doomsday scenario and nothing like the movie Outbreak. And yet it's still an emergency. (See pictures of soccer in the time of swine flu.)

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Before World War I, Presidents authorized their own emergency powers with little or no congressional oversight. The ability to do so stemmed from an implicit interpretation of the Constitution's requirement that the government "provide for the common defense and general welfare" of the nation. In 1794, President George Washington personally commanded a militia and used it to suppress a rebellion against a federal whiskey tax. Although he did not use the term national emergency, the Whiskey Rebellion was the first instance in which a President gave himself a one-time use of additional power. Abraham Lincoln took emergency action against the Southern states that seceded from the Union. Congress was not in session when he took office, so Lincoln enlarged the military and blocked the secessionist states' access to seaports on his own, calling his actions a "public necessity."

The Shipping Act of 1916, although mostly about maritime commerce, included a small clause requiring all national emergencies to be "declared by proclamation of the President." President Woodrow Wilson issued the first formal statement of national emergency the following year, on Feb. 5, 1917, in which he forbade American ship owners to sell their vessels to foreigners, arguing that they were needed to fight World War I. (See TIME's photo-essay "Landscapes of the Great War.")

Wilson's shipping restrictions were terminated in 1921, and the U.S. remained national-emergency-free until 1933, when Franklin Roosevelt proclaimed a national emergency so that he could institute bank holidays. Roosevelt never formally ended the emergency, and in 1973 an astonished Senate committee discovered that, technically, it was still in effect — along with three other so-called emergencies that collectively had activated 470 provisions of federal law. For 40 years, the U.S. government had accidentally authorized the President to seize property, control production, institute martial law and restrict travel at any time. Congress rectified this oversight with the 1976 National Emergencies Act, which terminated all existing emergencies over the next two years and put in place a series of rules by which all future emergencies would operate.

These days, national emergencies expire after six months unless formally continued by the President. After announcing an emergency, the President must indicate which emergency powers he plans to activate. In 1979, in response to the hostage crisis, President Jimmy Carter declared a national emergency, freezing all Iranian assets in the U.S. In 1999, President Bill Clinton declared a national emergency, prohibiting trade with members of the Taliban. President George W. Bush declared two national emergencies in September 2001, activating several obscure statutes, mostly related to calling up the armed forces. And although he proclaimed Hurricane Katrina an "incident of national significance," thus enacting a disaster-response plan headed by then Homeland Security Secretary Michael Chertoff, he did not invoke any powers under the National Emergency Act. This is common practice; natural disasters are usually declared state emergencies by the acting governor, who then requests federal aid. (See a bin Laden family photo album.)

The H1N1 declaration sounds more dire than it really is. Obama has neither seized property nor commanded any militia to combat swine flu. So far, he has only given the Secretary of Health and Human Services the ability to do things like allowing hospitals to transfer patients to special satellite facilities — something not usually allowed under federal law.

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