The South China Sea is a huge flash spot. The Spratly Islands stand over oil reserves -- Vietnam, China, Indonesia and the Phillipines all want a piece of the action: some of these nations station soldiers on stilt buildings to claim sovereignty. It'll take some hothead (like an ill-disciplined F8 pilot) to spark that powder keg.
The US is pretty aggressive about its Freedom of Navigation program around the world: surveillance is likely to be one of the methods it uses to monitor the sea lanes. Sometimes planes and ships bump (remember the Black Sea incident with the Soviets?).
There are a lot of bullies out there who would like to shut out the free movement of civilian vessels (the robber barons of Germany spring to mind as a group of trade thugs who got their just deserts eventually: hence the burning of the Rhine festival every year). Using military vessels to secure these sea lanes/airspace, the US ensures the rest of the world can trade (rah, rah, rah!).
Our service men and women are back: rejoice. They are not soldiers, but they are airmen, marines, and sailors who did their duty. For once, our government did its duty and got them back with minimum of fuss and grandstanding by the politicos.
Meanwhile, I'll celebrate my freedom these service members bought me by going down the pub and singing some chanteys tonight.
Hooah! Cheers,
Brian