SAC places the bombers on air alert, the missile crews batten down the hatches, the President dives into the airborne command post. Maybe issue a public apology. They do not launch their missiles. Meanwhile, the US is left with limited missile warning capability. We can't keep it up forever.
Spacecraft are expensive, launch costs are high.
It doesn't make sense to the bean counters to have replacement birds on any sort of alert. We CAN NOT regain capability quickly. The President is back in DC, working on the budget. Jim Horning once suggested that we need the equivalent of an Underwriter's Lab for software. It appears that such a thing now exists, at least for one professional group.