Colonel Daniel Reisner, former head of the Legal Department of Israel Defense Forces, justified Mossad's targeted assassinations by saying:

“If you do something for long enough, the world will accept it. The whole of international law is now based on the notion that an...

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act that is forbidden today becomes permissible if executed by enough countries.… International law progresses through violations. We invented the targeted assassinations thesis and we had to push it. [Now] it is in the center of the bounds of legality.”

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For many years the Hebrew term for assassination had been Hisul Memukad meaning “targeted extermination.” But in Nov 2011 Attorney General Elyakim Rubinstein mandated substitution of the phrase Sikul Memukad, meaning “targeted prevention,” which became the official term.

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In 2005, Avi Dicter, the retiring head of Israel’s internal security service, Shabak, was asked, “Do you have a problem with a state becoming an executioner?”

“No,” he replied. “I’m telling you, foreign delegations come here on a weekly basis to learn from us, not just..

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the Americans. It has become the sexiest trend in counterterrorism. Its effectiveness is amazing. The state of Israel has turned targeted preventions into an art form.” Dicter later coauthored “Israel’s Lessons for Fighting Terrorists and Their Implications for the United States”

Reference:
“Kill Chain: Drones and the Rise of High-Tech Assassins” by Andrew Cockburn