US troops have been in Sinai supposedly to prevent violations of the peace, since the 1970’s. It seems they just weren’t doing the job adequately is all, to allow the reported 10,000+ missiles into terrorist hands on Isr’s borders?
Their job is not to look for, identify, or prevent weapons smuggling. They are there on a string of outposts to watch for violations of the border lines by Egyptian and Israeli armed forces.
Up in that area, US Forces are not on the outposts, Colombian and Fijian units are.
The UN has no presence there.