Well I'm new here, so might be stepping on feet, but let me tell you a little of what I know. I was a soldier, and former law enforcement. I spent a bit of time in U.S. Army Stryker's.
Probably the biggest thing that people don't understand about modern warfare is just how advanced these vehicles, both ground and air. For example, with out data link the vehicle commander could see on a high quality moving satellite image map, all the other units in our command. (or whatever, depends on settings.) If we got a radio call that say, vehicle 1 (we're #3 in this example) was receiving fire from the west, we could see exactly where they were, where we were, and the area around both of us. We might see a building, a hill or other likely position for the enemy to be at. Using this it wasn't difficult for a commander to give separate orders to different units, and everyone knows where everyone else is.
Now aircraft use similar systems, and sometimes you can have an entire land-air-sea task force all data linked together. Meaning everyone knows where everyone else is. Furthermore aircraft such as the F35, F/A-18 C and Super Hornet, and F-16 etc all have helmet mounted cueing systems. This enables the pilot of let's say the old A-10, to look out of their cockpit and see a friendly ground unit (as long as everyone is on the same datalink channel) with a mark o their helmet display. The troops can the say, "enemy is 250 for 2 km from us." the pilot looks in the direct indicated, or simple tells their navigation and weapons systems "offset 250 degrees, 2000 meters from point A". Boom, now another mark is in the aircraft's system, the pilot can see it in their helmet and an attack plan can be formulated. If the distance isn't know, but the pilot see's a target indicator, they can simply look at it (in any of the aircraft mentioned, and many others as well.) and create a designation point based on where they are looking. Once that point is created the pilot can slave other sensors such as a targeting pod, etc, to the point. Now weapons can be employed.
In an urgent situation, a pilot of a modern combat aircraft can put warheads on foreheads in less time that it took me to write this, just by looking at it from their cockpit. Air to air weapons can work the same way. Several aircraft can see friendly and enemy units on projected on to their helmet visors from many different donor sources. if you want some idea's of how this works, watch some YouTube videos of Digital Combat Simulator and the F-16 or F/A-18 or A-10. Those data link systems are fully integrated into the simulator, and you can see what the symbology looks like from the pilot's perspective.
So, the amount of data a combatant get's today is something most people can't grasp. I read a open source story once that gave theories as to how the Israeli Air Force killed that Pansier system in Sryia a few years back. (Sorry I can't find the article in question) The theory was that IDF and Mossad got a phone number of a Sryian Air Defense Operator. They tracked his phone with A drone or some other platform, and basically followed him to work. They killed the SAM. Now I don't know if that's true or not, the point is, it's possible. Using a cellphone on today's battle field is a very good way to catch a cruise missile in the fact. We've seen this in Ukraine. Soldiers, on both sides, having a phone with them, "BOOM", a missile, rocket, artillery, or air strike. Radio direction finding has been a thing for decades, well back to the second world war. Today nearly every nation station, and many non-state actors have access to tech which enables cell phone tracking, etc. Social media companies are well know for selling and using personal data. Pretty easy for someone who is interested to learn that some person is a soldier, which food places they like to earth, etc. Track that person's phone (how many times have you seen a phone type and model listed at the end of a forum post or email?). Once intelligence has the phone, IP, etc, it's just a matter of time. The problem of course is that everyone has a phone, so there are mountains of data on everyone and it can take time to find the one specific person you're looking for. (but not much time if they really want to hunt someone.)
Next, I think I'd say the over blown propaganda of modern weapons. Sure, the technology is very advanced, but you'd be amazed how often a $500,000 bomb or missile just goes stupid. Because it's advanced, there is often programming to define the weapons parameters for release. If you transpose one digit of the coordinates, the weapon will miss the target.
More tech is often countered by other tech. How many people have said "the dog fight is dead, everything is BVR now..." and yet today in Ukraine the deluge of powerful, long range Surface to Air Missile systems has made flying high and shooting from far away impossible, there's just SAM's everywhere. This has been forcing combat aircraft to fly lower and lower. Fighters are running into one another at very low altitude, and well inside visual range. If they fly high, they die to a sam. if they fly low, there are manpads and everyone running into everyone else at close range. In my experience war's seem to devolve to close range brutality very quickly. I was told close infantry combat simply wasn't the done thing old chap... and ended up fighting an urban warfare counter insurgency and getting into gunfights at touching differences. Turns out the enemy, whoever they are, they get a say in how the war is fought. GPS systems are jammed on the battlefield to some degree daily. The Taliban even used this when that war was still going.
A GPS guided bomb, such as a GBU-38, might have a CEP of around 3-8 meters (I don't know the official number, but it's close to those figures) Add in some GPS jamming, and now that CEP might jump to 100 meters or more. Again, the technology is very advanced, but it often results in new challenges and limitations to everyone, resulting in 21st century war fighters engaging in 10th century close range combat. Tech is both a blessing and a limitation. A dumb bomb or unguided artillery shell isn't always accurate, however, some guided weapons (most all of them) won't allow release if they targeting parameters aren't met, meaning no drop. Now a fighter jet armed with the latest "smart'" weapons is limited to gun runs on a target, or something like that.
Now in my spare time I do write a bit of science fiction. I like writing about the smells, I think it makes things more immersive for the reader. In light of that, a battlefield smells. APC's and Armor have a very specific smell. Like diesel fuel, sweat, dust gun powder and explosives smell. I've been in a few combat aircraft, and while you smell it as much because of the oxygen mask, they too have a unique smell. Burning vehicles, to anyone who has every smelled them, isn't something you'll forget. People's bodies torn apart by explosives, gunfire, or crushed also smell differently to a person who has died of natural causes. War smells, ask anyone who has been around one. I'll personally never forget many of those, including the smell of human waste being burned after being mixed with diesel fuel.
Again, I'm new here, so probably strange for the first post. I hope this helps you out, and feel free to send me a message if there are any questions I can answer.
Good luck.
