With all due respect, I think you have a false impression of the Arabs- at least, from what I know, and from my personal experience. Contrary to how the western media- particularly the right-wing media- paints the Gulf States, these countries are not peopled entirely by bloodthirsty fanatics. Things have changed a great deal in Saudi Arabia over the last 10 years: it has become much more liberal and more tolerant. The UAE and Oman have always been so, and Kuwait is very tolerant too (a good number of Iranians there, for example).
Moreover, if we are to exclude countries from UN peacekeeping missions because of possible problems with infiltration from antisemitic jihadists, which countries are left? There have been plenty of volunteers for Daesh from European countries, and the US. Looking at the figures- which will inevitably be less than perfectly accurate, but will at least give us an idea- some 3,000 people left Saudi to join ISIS. France? Just under 2,000. Germany? 1,200. Turkey? Could be up to 10,000. In total, some 80 countries have had citizens join ISIS. If we exclude all of them, we would struggle to find enough soldiers.
https://www.pbs.org/wgbh/frontline/...imated 3,244 individuals affiliated with ISIS
https://www.icct.nl/publication/tre...:text=Share:,minors from roughly 80 countries.
So, while I take your point, I don't think this would present a serious obstacle to putting together a UN peacekeeping force. It's worked in Lebanon, for example- I don't recall any attacks by UN staff across the border into Israel. If countries can't effectively screen their armed forces for covert jihadists or other variants of terrorism, then any action, by anyone, is doomed to failure.
From your perspective, which countries would you suggest as being suitable for this task?