Faced with an expected avalanche of international criticism and condemnation over Israel's massive attack on the Gaza terrorist infrastructure, Israeli leaders on Saturday explained why days of incessant terrorist rocket fire had left them with no choice but to go on the offensive.

Reading a prepared statement in English to foreign media outlets, Foreign Minister Tzipi Livni noted that for days Israel had shown tremendous restraint even as "hundreds of missiles and mortar shells were fired at Israeli civilian communities, including 80 missiles fired on a single day."

But as the attacks continued and escalated, Livni said Israel was left with "no other option than a military operation. We need to protect our citizens from attack through a military response against the terror infrastructure in Gaza.

"This is the translation of our basic right to self-defense," Livni insisted.

Livni and the Foreign Ministry on Saturday embarked on a broad public relations campaign to counter the images Palestinians began immediately streaming out of Gaza and the wild claims by Arab leaders of an indiscriminate massacre.

As part of that campaign, Israeli UN Ambassador Gabriela Shalev shot off an urgent letter to UN Secretary General Ban Ki-moon and the head of the Security Council defending Israel's decision to unleash its might against Hamas.

Shalev wrote that Israel had "exhausted all means and efforts to reach and maintain quiet and to respect the state of calm" in and around Gaza, but added that "no country would allow continuous rocketing of its civilian population without taking the necessary actions to stop it."

Shalev stressed that Israel's assault is "aimed solely against the terrorists and their infrastructures in the Gaza Strip. It is not intended against the civilian population."

Meanwhile back in Israel, Benjamin Netanyahu and other leaders of the opposition pledged unity and support for the government as it directs the battle against Hamas and the other Gaza terrorists.