WASHINGTON – The government forecasts massive disruptions if bird flu or some other super-strain of influenza arises, with as much as 40 percent of the national work force off the job, but it doesn’t foresee closing U.S. borders to fight the spread, according to a draft of the national response plan obtained Monday.

An outbreak could lead the government to limit international flights, quarantine exposed travelers and otherwise restrict movement in and around the country.

But a complete shutdown of the border would not be likely, nor would it do more than slow the pandemic’s spread by a few weeks, according to the plan that is being finalized by Bush administration officials for release Wednesday at the White House.

The government is preparing for a worst-case scenario of up to 2 million deaths in the United States.

So far, the Asian bird flu, called the H5N1 strain, has struck more than 200 people since 2003, killing about half of them. Virtually all the victims caught it from close contact with infected poultry or droppings.

The report aims to energize the private sector, noting that 85 percent of the systems that are vital to society, such as food production, medicine and financial services, are privately run.

Included in the report’s advice for employers: Have workers remain at least three feet apart or otherwise limit face-to-face contact to limit the flu’s spread, including by working from home or substituting teleconferences for office meetings.

The report envisions possible breakdowns in public order and says governors might deploy National Guard troops or request federal troops to maintain order.

If a pandemic begins abroad, federal health officials are guaranteed to take certain initial steps, such as screening travelers arriving from affected areas and putting the possibly infected into quarantine.

With no border restrictions, pandemic influenza would arrive in the United States within two months of an outbreak abroad, the document estimates. But models of influenza’s spread suggest that sealing the U.S. border would not only be impractical – 1.1 million people cross the nation’s 317 official ports of entry daily – but it would only delay the inevitable by a few weeks, it says.

Meanwhile, British health officials reported in a medical journal Monday that closing international airports will do little to halt a bird flu outbreak.

“Even if 99 percent of international air were stopped, every country would in all probability still be infected,” said Ben Cooper of England’s Health Protection Agency and an author of the study in the online science journal PLoS Medicine. “Even if 99.9 percent of travel were stopped, very few cities would escape the pandemic.”