One thing is definite about this year's federal play-acting exercise to assess national emergency preparedness: A faux radioactive nuke, or "dirty bomb," will not be blowing up the Las Vegas Strip in May.

Reminiscent of Stephen King's "The Stand" featuring a similar cataclysmic showdown in Vegas, the preparedness exercise proved too much for many Nevadans, already battered by a poor economy and worried about a PR nightmare.

Sen. Harry Reid (D) of Nevada, in the midst of battling for the White House's healthcare reforms, wrote late last year that to "simulate a nuclear detonation in the heart of the city would unacceptably harm the Southern Nevadan economy."

More recently, President Obama had rankled Nevadans when he suggested that gambling on the Vegas Strip wasn’t the wisest move “when you’re trying to save for college." When Senator Reid complained about the comment, Mr. Obama was quick to apologize.

Will there be an exercise somewhere else?

Against that practical and political backdrop, the Obama administration scratched Vegas as the National Level Exercise host city late last year. That leaves the NLE 2010, which involves 10,000 responders, still on the calendar but without a practice field: DHS has yet to publicly announce the city – or even the scenario – it plans to use in mid-May. (It usually takes upward of a year to plan an NLE exercise.)

“NLE 2010 is currently in the final stages of planning for this spring," writes FEMA spokesman Brad Carroll in an e-mail. "We will continue to reach out to key stakeholders, including state and local officials, to receive their input as we prepare for and continue to develop this important event.”

The possibility that politics may have affected a national preparedness event rankles some Republicans on Capitol Hill, especially after Obama in July halted a Bush-era "scenario planning" program to review its effectiveness.

Canceling the Vegas exercise "just plays into the narrative ... that the public cannot handle any discussion of serious potential terror threats," writes John Solomon, a blogger who says he's writing a book about emergency preparedness. "As a result, it prevents our leaders from having an open dialogue which might actually improve our ability to respond."

But the president's supporters, including those deep inside the nation's emergency preparedness ranks, say the Obama White House may be shifting away from large-scale "open book" tests, practiced during President Bush's tenure, and toward "no-notice," or secretly planned, tests that thrust emergency managers into unexpected, sink-or-swim scenarios.

Surprise exercises may be a better test

"The administration is reasonably asking questions about how the NLE program is constructed, what are the outcomes, how are the lessons learned used, which is all fair game," says Craig Vanderwagen, who served as assistant secretary for preparedness and response in the Department of Health and Human Services until his retirement last fall. "There is a school of thought that says, 'Let's do some no-notice testing and see what we've got.' And if you judge by the intensity by which the president and the White House have directed reviews on a lot of these activities, [no-notice] tests are within the realm of possibility."

That would represent a major shift for a national emergency preparedness plan that spans local, county, state, regional, and federal agencies. Cooperation under that plan is often marred by inadequate funding at various levels of government, as well as issues that limit the ability of Washington to fully control response scenarios.

Changing the NLE would test Obama's ability to maneuver a maze of congressional oversight that has often failed to close basic gaps in national preparedness, including first responders' ability to use a common radio system to communicate with one another.

Meanwhile, the clock is ticking on NLE 2010.

"The tendency right now is to be more focused on biological events [such as a pandemic] as opposed to manmade disasters, but we can't ignore the fact that there are still bad guys with evil intent doing bad things that could involve radiation and nuclear," says Mr. Vanderwagen. "The impact on our society of such an event would be huge – the idea of not being able to use New York City for a generation if we had that kind of exposure."