I've been watching this loom for a very long time.
Basically...
China is building them, and won't stop. So everybody else also must.
Given the overwhelming strategic power that is on offer, the reluctance to set up a ban never gets anywhere. Many discussions at the UN, no progress. I bet every nation's military must have carefully considered them by now, and a ban must look like tactical suicide.
The possibilities are staggering:
[ul]
[li]Increased scope and detail in patrols (borders, no fly zones, etc.)[/li]
[li]Lighter vehicles (esp. aircraft) with higher maneuverability[/li]
[li]Land air and sea vehicles all carry more weapons payloads, need less safety protocol[/li]
[li]Fewer casualties; losing an "asset" does not mean losing a soldier[/li]
[li]Fewer soldiers can control more weapons[/li]
[li]Faster response to enemy movement, countermeasures and counterattacking[/li]
[li]Resistance to jamming (including superiority to remotely-operated weapons)[/li]
[li]Effects of fatigue, fear, injury are eliminated from battle outcomes[/li]
[/ul]
You could almost convince yourself it's a good idea. Until you think about everyone they can target...
Perhaps the only obstacle I can see is where allied nations do not permit each others' drones on their territories, even in mutual defense. Can you imagine some of the current NATO joint-patrol missions in eastern Europe being carried out by drones?