These are not the competent actors forged by WWII and the Cold War. That generation is mostly gone, retired or dead. Meritocracy is always one generation away from decaying into an informal aristocracy. The people who staff these agencies now, they haven't got the same drive. Ambition, perhaps. But it's a narrow, selfish ambition. The true believers end up crowded out by nepo-babies and self-interested bag grabbers. There was an era when any bonkers, long-shot pitch would get money and man-hours. That era is over. The money spigot is squarely the turf of private contractors.
Capitalism eats its own foundation and even the nat-sec dorks aren't immune to the long hospice of empire.