"Sequestration took effect at midnight on March 1, as congressional leaders were unable to broker an 11th-hour deal to prevent it from kicking in. The Pentagon, facing up to the possibility of no deal, has been hoarding cash since mid-January, repeatedly warning that it can't absorb the sequestration cuts without profound effects on the military, especially on readiness. Though war-bound units will have priority, the Air Force will have to lay off or furlough tens of thousands of civilians, and some flying units may be idled for months at a time. Returning those people to proficiency will be a long and difficult process, and in the meantime, the Air Force will indeed be hollow. Sequestration is just part of a "perfect storm" of fiscal crises affecting the service, though, as the never-ending budget continuing resolution and debt ceiling battles also take their toll."
The impact of the first quote may not be apparent. Civil servants in the military serve as the continuity that uniformed personnel usually cannot perform. Uniformed military personnel have to move around for promotion, learn new skills, or help improve unit readiness. Civilians remain in place and serve as subject matter experts. Furloughing civilians may have made sense since they do not deploy as part of a warfighting unit. However, support services and research will be tremendously hampered by these furloughs. And remember, these furloughs are across the entire federal government (except of course for Congress and the Senate).
The impact of the second quote may even be more arcane. The Air National Guard is responsible for air defense of the United States. It was the ANG that scramble F-15 fighters to intercept the airliners on 9-11. It was the ANG that flew combat air patrols (CAP) over DC and New York. Reducing flying hours means pilots skills are being compromised. It means maintenance crews are sitting around idle. Readiness will be effected and the longer sequestration remains in effect, the longer it will take to get those skills back up to speed.
The myth is that units and personnel being deployed to contingencies won't be effected. True, those rotations won't be effected but what about the cuts to training that take effect at home station? Even if the argument is training for deploying troops isn't effected, support and services for those that are not deploying will be cut. Readiness is still effect. Why? If you have not been on an active duty base, many of the functions one would think as being performed by military personnel are actually performed by civilians or contractors. Furloughs automatically reduce availability of services.
Sequestration will have broad and profound impacts on things we take for granted. Food inspectors are being furloughed. This could have the effect of reducing the amount of fresh produce available which will increase the cost at the grocery. Federal law enforcement will be affected even if sworn personnel aren't cut, their support personnel (technicians, clerical, maintenance) will be subject to furloughs.
The ability for the United States to respond to a national disaster or attack is now greatly compromised.