Which important individual military skill is the worst-taught?

Marksmanship in general is a problem. The way it is taught does not translate well to the battle field. Static potions with static targets is not reality. Marksmanship needs to work more towards action shoot sports. With movement and odd angles strong and weak hand shooting. All soldiers should be taught and practice these techniques not just before deployments.

I can just pick one. If you have a bad leader in the beginning that doesn't communicate well, then that goes with you,. If in basic you hit the bottom of the qual chart they still send you packing, with out proper training in the hope that the unit will teach you better. Hand to hand now a days sucks in the army. they teach you to fight on the ground. I want to learn how to kill the enemy in hand to hand and if I get down then I'll worry about that. This is the reason we where the best WWI, WW II, Korea. We fought to Live and survive. Not lay down on the ground and shrimp! Planning usually starts at the top and the bottom follows. If your leaders suck when you are young in the military and then roles down. they don't teach Planning they teach follow me. That's not always a good PLAN! Yes you have to follow but if no one teaches you to plan then in later years it will come to haunt you.

I voted plan, based purely on my own experiences , because it seems we teach junior leaders very limited planning capabilities but make them experts at putting out short term, 5 meter, targets. I think the reason we are so 'reactionary' at the Troop level is because we are not conducting planning right at higher echelons. A brief stint in the 3 Shop, and becoming a field grade officer should not be the criteria when we decide to teach our soldiers to look beyond the current week.

I believe all of our services do well at instructing marksmanship during their basic training. However, I believe we do a great job of range operations at our home stations - focusing more on the conduct of a safe range versus getting after the need to making on-the-spot corrections.

How do we fix our marksmanship training - it happens at the unit, well before going to the range. It happens during the last 15 minutes before Soldiers leave for lunch or before they go to close out formations. We have to make an investment in this critical skill which is really the purpose for every one of us serving, to effective engage and destroy the enemy...we do that by being able to shot them in the face.

We can and must most improve our marksmanship and you find your unit is having problems qualifying, there is an excellent training course available (Master Marksmanship Course http://www.military.com/daily-news/2015/02/27/course-aims-to-improve-marksmanship-across-army.html )

It is imperative that our force is grounded in rifle marksmanship fundamentals and are willing and able to engage and destroy the enemy with precision shooting.

So I'm going to say we're the very worst at all of these. I can't count the number of times I have been ANGRY, like table-flipping mad about failures in each one of these. It's like they're unending.

But you know, we're better than everyone else at them too. The other militaries I've spent time with don't hold a candle to us on any of these. We are the very best at all of them in aggregate. So like Churchill kind of said "We are the worst, except for all the others."
But that's a cop-out. I force other people to pick one so I'm going to also:

Planning.

When anything fails it is a failure in leadership A failure to train or to communicate or to prepare properly. And that means some leader, somewhere failed to plan properly.

How do we fix it? Hold eachother to the standards. Think critically, challenge 'the way it is' and make it make sense. Remember our purpose, what mission accomplishment means: being the most lethal fighting force out there. Be ready to drop stuff that doesn't serve that.

That great good also resides within every human being just as the ability to kill.

Teach! We don't teach our instructors how to teach. Teachers and educators go through years of school to become entry level teachers. then they practice their skill year after year, day after day. We go though about a week of "how to make a power point presentation" then send our newest instructors on their way!