Just before lawmakers agreed to delay the cuts, the Pentagon began preparing official notification to Congress that all civilian defense employees faced furloughs of up to 22 work days – about one calendar month.

But it was not clear how many employees might actually be furloughed or for how long. The congressional notification was put on hold after the cuts were postponed.

Harrison said according to his rough calculations, if sequestration takes effect March 1 virtually every civilian employee would have to take unpaid leave for a month before the end of September to achieve the required savings.

The budget for civilian pay and benefits is about $70 billion a year for about 791,000 employees. Under sequestration, spending would have to be cut 8.8 percent for the year. But since five months of the fiscal year have passed, the necessary cut to the remaining funds would be about 15 percent.

“If you’re going to reduce your payroll expenses by 15 percent for the remainder of the year and you’re going to do it through furloughs, that means you have to furlough virtually every single DoD (Defense Department) civilian for the maximum amount of time you can under the law, which is one month,” Harrison said.

He said the spending reductions also would create a “nightmare” by forcing the renegotiation of many Pentagon weapons contracts, work that would have to be done by some of the same civilians forced to take unpaid leave.

Harrison said he wasn’t convinced the cuts were “the most likely outcome yet” but said “the odds of sequestration going into effect now, I think, have gone up.” Delay was also a possibility, he said, “but at some point delays run out.”

While sequestration would “create a real mess” for the Pentagon, Harrison said he disagreed with some of the “over-the-top rhetoric that has been coming out about this.”

“I don’t think this is the apocalypse,” he said. “I think it forces a lot of really stupid decisions. I think it’s very short-sighted. But it’s not the end of the world. We’ll survive it if it happens.”

If Congress does reach a deal to avoid sequestration, Harrison said he thought it would include some $200 billion to $300 billion in defense cuts over 10 years, with the Pentagon being given the latitude to target the reductions over time.

“If you have a more gradual ramp-down at about 1- to 2-percent real decline per year, that would give you significant deficit reduction and it would enable DoD to start making smart, strategically informed choices about what they put in their budget request,” he said.