I believe there is no "most advanced" military.
The U.S. is very advanced, yes. This does not mean we are THE MOST advanced.
When it comes to the most technologically advanced military weapons currently used, yes wer are.
But you have many countries that are advanced in different areas of their military. Like, for instance, Isreal's defensive weapon technologies are vastly superior to ours, in my opinion. Japan has robotic prototypes, AT type walkers, etc., that the United States, as far as we know, doesn't have. A military is only as advanced as it's main priority, and usage of it's technologies, we, as a wrold, have far more advanced technologies, already in testing, that the average public couldn't comprehend. No military is going to release their most advanced weapons to the public eye. The United States may have far more superior weapoins compared to most countries, but we don't see the need to put the best out, when we are already ahead by several decades in military technology, with even some of which that was introduced back in the 70s and 80s, and many countries cannot even keep up with those. Not saying all can't, just the majority. Unless the whole world started to use their most advanced technologies, there is no need to bring out the best at this point and time. Same goes with third world countries, they do not rely on technology, they rely on their war experience, which the U.S. in comparision to the world, does not have as much of. I do believe that no one country should rely too much on advanced weaponry, machines, technology, etc. What happens if a supposed solar flare/ solar storm hits Earth and all of our electronic devices were deemed unusuable? The world goes in chaos, and wars start, then it comes down to the better trained warrior(s). I do believe American soldiers are not the best trained, so we would potentially be screwed if something of this magnitude were to ever take place. Any situation, person(s), etc. can decide a war, technology is only one of the many factors that come to play in war. We, as a species, presume technology is just computers, and advanced machinery, which this is not the case. There, in our known world, will never be a most advanced military, simply due to the fact that no one country knows of every other countries technological capabilities, etc.