The motto of the US Army Infantry is "Follow me". Every infantryman from the lowest private to the highest general is expected to lead the way regardless of the personal danger. The Elite of the US Army Infantry are the Paratroopers, and in the Airborne the Officer is always the first out of the plane. First to hit the DZ, and first to get shot at. When the 29th Infantry Division landed on Normandy beach the mission had gone all to hell, it took a Sergeant here a Lieutenant there, to create impromptu units, and storm the fortifications. Once the Engineers were able to clear the majority of the obstacles the Assistant Division Commander for the 29th Infantry Division, Norman Cota, in overall command of what was left of the first wave turned to Major Max Schneider, the commander of his most elite unit under his command, 5th Ranger Bn, and ordered "Rangers, Lead the Way!" They did, and still do today.
In the Korean War (then) Captain Lewis Millett lead two platoons up a hill, to relieve another platoon that was pinned down, in one of the last bayonet charges in military history. He was up front leading the way, throwing grenades, and charging the Chinese position, and actually overrunning the Chinese trenches. For his actions he was awarded the Medal of Honor. In Vietnam, during the disastrous Lam Son 719 again and again US Helicopters were shot down, and again and again, the pilots would get back int their choppers and go back out, no one would order them to go back after their comrades, but they went anyway. These are all great examples of Leadership in the military. See in the American military Our men are not cannon fodder, our soldiers are expected to be quick to adapt to change. Our leaders lead as close to the front as we can get them because if you don't know whats going on how can you possibly lead?
At all levels, you have to be decisive, in your actions, you have to be out in front. Much like the Spider-Man Franchise, again and again it is drilled into the Heads of the NCOs and Officers, that With Great Power comes Great Responsibility. When you're Soldiers are taking five on a Ruck March, you've got to get up, on your tired dogs and walk up and down the line, making sure your soldiers are hydrating, and if its a tactical Ruck March, that they're pulling security and not just passing the hell out. You're the last to rest, and the first to get up. The responsibility is yours but so are the rewards. Rank does hath its privilege, but those that abuse that privilege will soon find that their ability to lead is drastically reduced.
With all that in mind how do you translate that to the civilian world. Well I wish I could choose any other example that the POTUS, but really its so painfully obvious it needs to be done. See The major problem with being the POTUS is that if you screw up you get blamed, if someone else gets it wrong, you get blamed, and really if there are factors that are beyond your control, you get blamed. Herbert Hoover is one of the greatest examples of a President that got bushwhacked by something he couldn't possibly have foreseen or even controlled. Bush the Elder got something along those lines too. With that in mind you also have Presidents that somehow rise above everything. Washington, Lincoln, Eisenhower, and Reagan are perhaps best examples of this. Why? Because they knew how to lead. Each had their own style, Lincoln would actually give direct orders to his commanders in the field, and was constantly on their backs to be aggressive and attack. He could micromanage the snot out of a ton of things, and yet he found a balance that worked. Conversely Reagan liked to delegate. He knew how to pick the best people for their job, and knew how to let them job. He deftly inspired America to believe in itself, held to a course of action and was greatly rewarded for it. He had failures to be sure. Beirut is a great example, as is Iran Contra, here there is also a lesson for a prospective leader; know when to take responsibility for your failure. Despite some failings, he almost single handedly defeated the Soviet Union. Our Current president despite being an excellent orator, is not a leader, tending to want others to take the risk, and wanting to swoop in in time for the reward.
Being a leader is going to be stressful. Its not for everybody. Some people want to control every aspect of a situation, and micromanage things into oblivion (see President Johnson and Operation Rolling Thunder). They can also delegate too much, to the point where they really aren't in control of their administration (See the Grant Presidency). Its a balancing act. One thing is clear, that in America at least loyalty is not one way. Sure the little guy has to be loyal to the big guy, otherwise things just wouldn't get done, but if the big guy is not loyal to the little guy, or more importantly doesn't listen, it can be just as disastrous. If I wanted to point to any circumstance where down chain loyalty was desperately needed (on both sides) I would point to the Easter Front in WWII. Both the Nazis and Soviets saw their soldiers as expendable. To be clear, they're not.
One of the most important traits is decisiveness. Yes, listen to your people, especially when its on a subject where you are not the subject matter expert. I do not expect an Infantry Captain to know where exactly the solid organs are, and where the hollow ones are, but I do expect him to listen to me when I say a patient is critical, and needs to be evacuated ASAP. I also will expect, that if Evacuation is not possible, or if the risk is unnecessarily high, despite the fact that the soldier in question may die, the Captain will not waffle, he will make a decision and stick with it.
I would also caution any prospective leader. Beware how close you get to those you lead. At some point you will have to make a call that might upset or disappoint them. In the Army you may make a call that gets them killed. At the moment you make those calls you have to be able to put your friendships and dislikes out of your mind and choose what is most appropriate for mission success. If that means that your RTO goes to an extremely exposed area to call for support, then you have to send them, quite possibly to their death. But even in the civilian world there will be times when you have to make hard calls. Bob may be your friend, and you may like him a lot but that Dick, well he knows how to get the job done and despite how much of a dick Dick is to Bob. Bob gets the job done, but not as quickly or as efficiently, wanting his team to "like" him, rather than put too much stress on them. Dick would probably be better in a position of responsibility. . . well the choice, and consequences are clear.
Ultimately you will not know if you have what it takes to be a leader until you step into those shoes. If the idea frightens you then I suggest you never try to be a leader. Timid leaders, or leaders who utter the phrase "I Don't Know" are worse than no leaders at all. Uncertainty is anathema to a true leader. Yes doubt will claw at your gut, but if you let it get to you, then you ought not take that position of responsibility. If you are going to Lead, then by God, you had better Lead. Anything less and you are setting yourself and your team up for failure.