VERY care fully. They neither threatened Israel OR attacked any of it's newly declared Sovereign territory at the outset of war 1948. There is no UNSC resolution condemning the Arab Leagues action. They were the representative of the non-state entity of Palestine. By May 15th, Israel was no longer a part of Palestine. As regional (collectively and singularly) power's, under the UN Charter, they had every right to protect their ward from Jewish forces already over Israel's newly declared Sovereign boundaries at the moment the Jewish People's Council accepted and declared Sovereignty over the boundaries of UNGA res 181. The Arab League attacked Jewish forces OUTSIDE of Israel on May 15th 1948. As war progressed they also attacked armed forces and persons inside of Israel. (which is quite legal in once a war has started). The Arab Declaration does not threaten Israel. It OUTLINES the legal case and says very clearly at the top 'Declaration on the Invasion of PALESTINE'
Former ruling party in Yemen says it accepts UN-brokered peace plan (Reuters)
from the article: Report: Syria willing to consider phased Golan pullout