A good M-4 type with an A.C.O.G., Holosight or Aimpoint, and you're well armed.
A properly placed round of M193 ball will kill anything you need to kill, and you can carry a helluva lot of them for the same weight as a small handful of 7.62X51.
History fails to record a single precedent in which nations subject to moral decay have not passed into political and economic decline. There has been either a spiritual awakening to overcome the moral lapse, or a progressive deterioration leading to ultimate national disaster.
If you think a strong military is expensive, think about what a weak one would cost