Re: I don't understand why they need it
In 2016 45,000 Isis fighters and 3 US soldiers were killed in the conflict.
The US did very well to kill 45,000 IS fighters in 2016, given that the CIA estimated in early 2015 that IS could field 30,000 fighters. The most authoritative data source, the Syrian Observatory for Human Rights, estimates for 2016 were that "only" 21,500 anti-government combatants were killed, including Kurdish and non-IS militias. SOHR estimate that the number of IS fighters killed by the US was around 8,000 across the entire five years of the conflict.
Personally I see a 15,000 to 1 kill ratio as evidence of a strategic military advantage.
Do you now? Not only are your numbers crap, but you need to stop focusing on a Black Hawk Down style bodycount, and consider the military outcome. The US has reinforced the position of its enemy Assad, it has further stirred up Islamic discontent (as if it hadn't done enough of that elsewhere), it has failed to change the extremist narrative, it has failed to capture and contain the escaping fighters, and (as in all of its other colonial wars) it has failed to bring about a peaceful and lasting resolution. It has strengthened the regional hand of Iran, and reinforced Islamic sectarian divisions. And I might add that much of the weaponry and training of IS was actually provided by the US who were trying to support opponents of Assad. US costs so far in Syria are around $20 billion, judging by reports to Congress. So each IS fighter killed cost the US taxpayer $2.5m. You still call any of that a strategic advantage?
So I think my point stands - with command of the air (or LEO) you can rain death on poorly armed peoples with impunity. But it doesn't represent any advantage if it doesn't solve the conflict. And it is actually a strategic disadvantage if the actions simply spreads the conflict. Look at the facts: Since at least 2001 the US has been playing whack-a-mole, with a total bill credibly estimated at over $5.5 trillion. Every time it lands what it claims is a winning blow and announces the defeat of the enemy, job done, the mole pops up somewhere else. Tell me again, who's winning?