[QUOTE=Paul in Saudi]
No military has managed to work for long without a distinction between officers and enlisted men. The Chinese gave it the good college try and the system re-arose long before it was officially reestablished. The old Red Army same way.
[/quote]
I don’t think there was any real attempt to eliminate officer/enlisted divisions in the Red Army after the it was formed from the Red Guard. Despite Trotsky’s efforts to eliminate class barriers, awaken the political consciousness of conscripts, et ceter, the command structure and NCO corps of the Red Army were largely drawn from the Imperial Russian Army. The Red Army was shattered by the bloody purges of the 1930s, with the NCO corps particularly damaged. As a result, the Soviet Army was always top-heavy with officers who often performed the duties that were nominally the responsibilities of NCOs in Western armies.
[QUOTE=Paul in Saudi]
Next, the job of a junior officer is much the same as that of a senior NCO, with the single exception that the lieutenant is being groomed to command, while the sergeant is not.
Finally, being an NCO is much more fun than being an officer.
[/QUOTE]
I’m not military, so my experience is second hand (from observation rather than immediate experience as one or the other), but I’d have to take issue with the former statement. The job of JOs is really to stand around and learn, and provide a link between the senior NCOs (who tell the enlisted men what to do and how to do it, often at elevated amplitude) and midlevel officers (captains and majors, or in the navy, lieutenants and lieutenant commanders). Typically (but not always) officers are management generalists, and a JO is not expected to know much of anything practical (very few are promoted from enlisted ranks), and instead mostly stands around confirming the orders of senior NCOs who oversee activities. A good JOs relies on his NCOs to do pretty much everything but hold his hand while going to the bathroom, and as the officer advances his direct contact with enlisted generally decreases, at least for command-oriented tracks. Officers on for officers on technical, medical, or specialist tracks this may be very different.
Technically speaking, only a commissioned officer (one whose authority is derived from a soveriegn authority and who is thus in the chain of command) can give orders, but as a practical matter the actual functions of a unit are controlled by its NCOs and the officer takes responsibility (for good and bad) of the results, which is where the whole “leadership” aspect comes in. In the British tradition (upon which the American military structure is based) commissioned officers are drawn from noble ranks, and soliders/seamen (who were frequently conscripted or impressed into service) had almost no opportunity to advance into these ranks, lacking peerage or land. Although there is no such explicit caste system in the United States, officers are almost exclusively drawn from the military academies and Reserve Officer Training Corps, whereas the modern British Army and Royal Navy make a concerted effort to commission from the ranks.
As a practical matter, even with a complete ignorance of insignia you can tell easily tell enlisted from officers these days by the fact that the grunts are alternatively working hard or sitting around making fart jokes, while the officers are constantly tapping away on their Blackberrys. 
Stranger