Looking at this tactically, I am not the only one to spot a problem. Lt Col Dade, USMC (Ret) wrote an excellent piece describing the folly of weapons states in the AOR. He describes weapon status Green (condition 4--no mag loaded), Amber (condition 3--mag loaded, no round chambered), and Red (condition 1, round chambered, safeties on). Based on my trip to Afghanistan a few years ago I'd say that condition Green and Amber is very common, especially on ISAF/NATO bases. I rarely saw "Red" authorized anywhere inside the wire.
Dade highlights that the root cause is a lack of training which impacts both safety and efficacy. I tend to agree. Military gunhandling -- especially pistol handling -- is often poor due to marginal training levels. Historically the military has put more emphasis on rifle marksmanship, which makes sense, but if there is actually a significant threat inside the wire then handgun work becomes more important.
"Robust Weapons Handling" Training
However, I am kind of pessimistic about the ability of the military to implement "robust weapons handling and employment procedures that mirror law enforcement" as Lt Col Dade suggests. What would that entail? I think about the Defensive Handgun I course I took with Alaska Tactical. Such a course required 24 hours of instruction over three days and went through around 500-800 rounds of ammunition. So let's use that as a baseline.
A typical E-5 (NCO) has a total compensation of around $54K/year which is $150/day. 9mm ammo is running about $0.30 per round so that'd be $150 of ammo for 500 rounds. Then you need to factor in the costs for building and running additional ranges as well as acquiring trained instructors along with the increased wear and tear on M9s which would incur armorer time and expense. At a minimum it would be in the ballpark of a grand to put a soldier through a quality 3-day defensive handgun course that gives them the skills necessary to use an M9 skillfully and safely.
You could come up with a trimmed down program that focused on dry-fire, perhaps incorporated some computer based training or self study prior to the course start to cut down on classroom time, and maybe made use of simulators or lasers to cut ammo expenses. Still, just given personnel costs alone I think it would be tough to offer the training for less than $500-750. Realistically most soldiers issued M9s will continue to receive a one day fam and qualification course with somewhere around 100 rounds utilized.
While I generally frown upon equipment solutions to training problems this might be a case where an equipment solution is appropriate. In WW2 we solved this problem by issuing the M1 carbine. The M1 carbine was perfectly appropriate for vehicle crews and rear echelon troops who needed a relatively compact long gun. While there were some issues with stopping power especially outside 100 yards a carbine is appropriate for support troops.
The marines have also realized the benefits of issuing long guns for defensive use as they've transitioned over large numbers of officers and warrants to M4s. Issuing M4s is a good option. While many knock the 5.56 cartridge, I feel pretty comfortable using an M4 for defensive ranges. Heck, my bump in the night weapon is an M4gery. Shots that are hard with a pistol are trivial with a carbine. Moreover, with an M4, all the M16 training from boot camp should carry over just fine. However, the problem with the M4 is that it is still relatively heavy and expensive.
I think there needs to be an interrim solution that allows the large number of M9s still in service to be utilized but also mitigates limited training. The solution I'd propose would be a carbine conversion kit. A carbine conversion gives a stock and longer site radius as well as the option to mount an optic, all of which will help troops with minimum training deploy a weapon more effectively.
There are some options out there now for other platforms like the Mech-Gar CCU kit, the SIG ACP and KPOS. The RONI is available in SBR format for the M9 already. Beretta even made a variant (the 93R) with a folding buttstock option. These options run around $350. I suspect that if the Army made a mass buy with a large number of units the price could be reduced substantially. Heck, Kel-Tec manages to sell a whole complete carbine for under $300.
If you assume that we're stuck with the 9mm round due to NATO, the Beretta M9 platform due to financial constraints, and limited training due to time and expense realities, then a carbine kit in the $100 to $150 price range would go a long ways towards mitigating training shortfalls and enhancing defensive capabilities inside the wire.
A carbine gives longer site radius, the option to mount optics/lasers/lights if the mission required, and a stock to improve stability. You may also get a longer barrel depending on the design of the kit to give an extra 200 FPS or so, eking a bit more performance out of the 9mm. I feel like you could train a REMF or Fobbit to utilize a pistol caliber carbine at typical defensive ranges (inside 100 yards with a focus on the 3 to 50 yard area) relatively quickly and easily compared to the time and expense of a proper defensive handgun course.
A kit would give local commanders more options. For example, maybe at lower threat levels the kits are to be available at work centers or barracks, at moderate threat levels the kits to be carried, and at higher threat levels the kits to be installed. Maybe only a few folks in each work center need a carbine kit. Maybe even fewer need a carbine kit with an optic or weapon mounted light based on the threat.