Two wrongs don't make a right. Also Israel doesn't just kill Arabs, they kill terrorists. In case you didn't read the article the guy assassinated was a HIGH RANKING GAZA MILITANT. Don't forget Egyptians are Arabs to and they helped Israel kill this man.
U.S. says working on initiative to de-escalate Syria fighting, with focus on Aleppo (Reuters)
from the article: Israel issues severe travel warning: Al-Qaida may attack in Sinai