If the government shuts down Monday night, America’s national security and intelligence agencies will be operating with less staff, and the risk of an attack or other national security incident will go up, according to officials and experts.

“If we experience a partial shutdown, the intelligence community’s ability to identify threats and provide information for a broad set of national security decisions will be diminished for the duration,” Shawn Turner, the spokesman for the Office of the Director of National Intelligence, told The Daily Beast.

“The immediate and significant reduction in employees on the job means that we will assume greater risk and our ability to support emerging intelligence requirements will be curtailed,” he said. “The fraction of intelligence community employees who remain on the job will be stretched to the limit and forced to focus only on the most critical security needs.”

The Pentagon has said it will furlough 50 percent of its civilian employees if the government shuts down, and Deputy Secretary of Defense Ash Carter said Monday a shutdown “will be extremely disruptive and unfortunate, especially for the men and women who are defending this country who now have to worry about receiving their paychecks on time.”

Others are skeptical the shutdown will do real, immediate harm to America’s national security. They point to the fact that even top officials shy away from getting into the specifics of how the shutdown raises the risk of an attack or makes the military’s missions overseas harder.

“They can’t specify specific security consequences because they don’t know,” said Gordon Adams, former national security division chief at the Office of Management and Budget.

The real costs are the estimated $2 billion it costs the government to prepare for a shutdown and the estimated $2 billion it costs to get the government up and running when the money starts flowing again, including penalties for paying contractors late, said Adams. Plus, the confusion and chaos a shutdown causes can have its own negative impacts.

“It costs you money to turn off the tap, it costs you money to turn on the tap and some things don’t get done,” said Adams. “You can’t discount the consequences. You don’t know what will get lost in the wash when it happens, but it doesn’t imperil the national security of the United States.”

Defense and intelligence agencies will have to prioritize during a shutdown, Adams said. For example, analysts working on the Syria crisis will probably continue to do what they are doing, but routine intelligence gathering related to a country not in crisis might be temporarily set aside.

Other experts said the real damage to national security is that top employees will flee the dysfunctional environment of the federal workforce in favor of more stable and perhaps greener pastures.

If the Pentagon furloughs 50 percent of its civilian workforce, those employees can’t pursue other work and may even have to start paying for their health insurance and other benefits out of pocket if the shutdown lasts long enough.

Those employees may or may not get back pay when the shutdown ends. Put together, all of these hassles are likely to push top national security people away from a career working for the Defense Department, especially considering they already are losing pay and work hours due to the sequestration budget policy that went into effect last year.

“The threat here in terms of national security is more of a long term one,” said David Kamin, a former top OMB official now a law professor at New York University. “You’ll see a degradation in the employees’ motivation and in the agencies’ ability to recruit. These are employees already being effected by furlough brought under the sequester. They’ve already taken a pay cut. I would worry about the long term health of some of these very important agencies”

Across the national security bureaucracy inside the federal government, different agencies are preparing for a possible shutdown in various ways, but all claim that there will be some effect on our nation’s soldiers, spies, and diplomats’ ability to do their jobs.

The Anti-Deficiency Act mandates that no agency can spend money not appropriated by Congress, with certain exceptions, such as when money is needed “for emergencies involving the safety of human life or the protection of property.” But each national security agency – DOD, State, ODNI, and DHS – has developed contingency plans for the shutdown, specifying which employees can still show up for work and which functions will continue even while the government is shut down.

The DHS guidance for the shutdown states that some activities will continue, including criminal law enforcement, passenger and cargo inspections, Secret Service protective services, and counter terrorism intelligence gathering.

But several other sets of people working at DHS will be furloughed if the government shuts down, including those who work on policy, strategic planning, research and development, auditing, and legislative and public affairs. The domestic nuclear detection office, for example, will only retain 6 of its 115 employees.

Somehow, the State Department has managed to avoid furloughing large amounts of employees during the first few days of a shutdown. State Department officials said that is because many of its accounts are appropriated more than one year at a time and because State didn’t receive this year’s funds until March, so there is still money in most accounts to keep most offices and all foreign posts open for a limited but unspecified amount of time.

Not only will almost all State Department employees be required to come to work tomorrow if the government shuts down, but unlike their other national security government colleagues, they will continue to get paid as well.

“I wish to reiterate that Department offices, bureaus, and State elements at our posts overseas will continue to function for a limited period of time even if no new appropriations bill or continuing resolution is enacted by October 1, 2013,” Undersecretary of State for Management Patrick Kennedy wrote in a Monday memo to State Department personnel. “Employees and contractors should report for work on Tuesday, October 1, 2013, as usual, and continue reporting to work until instructed otherwise by my office. These Department employees will be paid for their work on the regular schedule.”

Still, there will be big changes for diplomats as well. During a shutdown, State Department officials can’t attend conferences or plan any official travel, according to a guidance memo the State Department issued last week. State Department officials can’t make public speeches or hire new staff. Embassies will remain open and continue to issue passports and visas. Secretary of State John Kerry will still travel on his coming trip to Asia, officials said.

Kenneth Baer, former OMB senior official, said that even if diplomacy doesn’t go on hiatus during the shutdown, there is a detrimental effect on America’s standing and reputation around the world.

“There’s a foreign policy impact when the greatest democracy in the world can’t seem to keep its government open. It’s a bad example for other countries,” he said. “On a practical level, while the most essential personnel needed to keep our country safe can come to work, there’s a lot of people who support and work with them who cannot, and over time that will degrade our ability to conduct our foreign affairs.”