What keeps the Arab world from leading a war again on Israel could be the power the USA. As long as they know that we would support Israel with determined resistance, they will probably not try anything. But the USA had some serious problem where we could use our forces very much, would most of the Arab world use that opportunity to unite against Israel? Are they waiting for just the right moment. Israel has a formidable military and in years past they tried and failed to defeat Israel. But I don't think that would stop them from trying again.