The Saudi Foreign Minister is 1/2 correct. Preconditions over borders does meet the criteria over trying to have your way before negoiations even begin. The extent, if any, of border modifications from 1967 is not a pre-requisite for Israel's continued existence and any demand of what will be negotiated does smack of trying to fix the end result before the process has begun. On the other hand, no one willingly enters negotiations if the desired stated intention of the other side is to destroy your very basis of existence. The number of refugees accepted back maybe, but anything that threatens two states for two peoples is a non-starter. Israel has the right, and even the responsiblity, to request that this initiative pull back from its stated demand of an unlimited right of return. Something more like seeking justice for the refugees including reviewing posible compensation, resettlement in other countries, and the extent of the right of return is far more reasonable.
U.S. confirms ISIS computer expert killed in air strike (Reuters)
from the article: Arab leaders rule out amending Saudi proposal