(Iraq) For years now the US has migrated over to Precision Guided Munitions (PGM) in which to accurately target the enemy, and reduce collateral damage. The problem is using weapons such as JDAMs, SDB, Paveway and Hellfire costs a lot of money What the US has needed is a much cheaper PGM which they can afford to use on mass which will kill the enemy a lot cheaper. Yes that sounds awful, but when you are trying to combat a movement such as ISIS, but have to answer to every man and his dog regards how you go about wiping out idiots such as ISIS (unlike the Russians who have simply carpet bombed their target area clear of idiots) then costs can restrict your ability to fight a protracted battle.
Most armed forces use rocket pods, which fire unguided rockets which are cheap plentiful, but as mentioned somewhat unaccurate , BAE systems have hit on the idea of affixing a laser warhead onto a hydra rocket and hey presto, a mini cheap PGM. Welcome to the Advanced Precision Kill Weapon System or APKWS which is a third of the cost and size of most conventional PGMs but rather than rabbit on, here's a wee video which tells you all you need to know.
A time line chart
Well as of yesterday the United states Marine Corps have started fielding the APKWS into theatre, starting off with the AV-8B Harrier II aircraft forward deployed to Bahrain.