Argument: The military operations were necessary for long term peace:

As Michael Oren and Yossi Klein Haleviargue explain, “the Israeli public will not make territorial concessions on the West Bank or the Golan Heights if Gaza is allowed to become a neighboring terrorist state that can launch attacks with impunity. Israel had already had a bad enough experience letting that happen with Hezbollah in Southern Lebanon.”(1) Without the assurance that they will be allowed to protect their homes and families following withdrawal, Israelis will rightly perceive a two-state solution as an existential threat. They will continue to share the left-wing vision of coexistence with a peaceful Palestinian neighbor in theory, but in reality will heed the right's warnings of Jewish powerlessness.(4)

Meanwhile, the stronger Hamas becomes, the more resistance moderate Palestinian President Mahmoud Abbas will face to making any concessions to Israel.(1) Therefore damaging Hamas, via Operation Cast Lead, actually aided the peace process in the long run, and was necessary in order to make an eventual two-state peace solution possible. The Israeli attacks may also eventually help force Hamas to accept a more durable ceasefire. Unlike the botched invasion of Lebanon in 2006, when Israel set itself the unattainable goal of eliminating the military capability of Hezbollah, during Operation Cast Lead it was made clear that the objective was not to wipe out Hamas, but instead to force the radical group to accept a durable cease-fire on Israel's terms.(8) This was necessary as prior to Operation Cast Lead Hamas showed no interest in peace, opting instead to pursue its political objectives through the use of terrorism. When Hamas came to power in Gaza in January 2006, it failed to control the rocket fire from the variety of miltary brigades, including its own al-Qassam brigade, into Israel and failed to establish internal stability. The widespread violence between Fatah and Hamas, which ended in June 2007, when Hamas took control of Gaza and ousted leaders of President Mahmoud Abbas's Fatah movement, made Israel more wary of the security threat an unstable Gaza could pose.(9)

In Israel's view, Hamas' behavior and its reliance on terror tactics will never change if it thinks it can attack with impunity, and so the Israeli military operations were necessary and justified in the name of restoring Israel's deterrent and weakening Hamas, both of which make long term peace more likely.

Candidate 1: "The long-term security of Israel rests in a stable peace agreement with the Palestinians, not in attempting to bludgeon Hamas into a truce 'on Israel's terms'. To the extent that Israel's large scale assault on Gaza eliminated the hopes of such an agreement, the attacks worsened Israel's long-term security.

A crucial step towards peace is to bring Hamas to the bargaining table. Israel's levelling of Gaza emboldened Hamas' message of resistance, and allowed Gazans to continue to rely on Hamas. As long as Israel continues to justify Arab and Palestinian anger through its disproportionate response, it is unlikely that enough trust can be established to reach a peace deal.

Even Israelis recognize that this assualt has created an even larger barrier to peace. “This policy [Operation Cast Lead] is not strengthening Israel,” noted Sari Bashi, the executive director of Gisha, an Israeli human rights group that works on Gaza issues. “The trauma that 1.5 million people have been undergoing in Gaza is going to have long-term effects for our ability to live together."(10)"
Candidate 2: "Under the same logic, over 1 million residents of Gaza have been under occupation since 1967, facing limited rights of movement, regular air raids, military checkpoints, random searches and seizures, random arrests, the destruction of sanitation facilities, homes, schools, roads, shops, markets, and health facilities, and therefore Hamas has the right act in its own self-defense by whatever means it sees fit. If Palestinians do not have an army to call to its defense, how can the entire population be punished for the actions of non-state military groups?

Israel’s right to take positive steps of some kind in the interests of its own safety does not mean it has the right to do anything it wishes in order to protect itself. It is also evident that Israel violated international law and committed war crimes, was was reported in the Goldstone Report.

Between the time when the shelling from Gaza started in 2001 and Operation Cast Lead, 20 Israeli civilians were killed by rockets or mortars, according to estimates by Israeli human rights groups. That doesn’t justify an all-out ground invasion that killed more than 1,400 people.(10) As Javier Solana, chief of foreign policy for the European Union, said in late December 2008, "the current Israeli strikes are inflicting an unacceptable toll on Palestinian civilians."(14)

It is a widely accepted principle of international law that actions taken pursuant to a state’s right to defend itself must be proportionate to the danger that the state faces. While the 20 deaths that resulted from the actions of Hamas and its associates were tragic, the nature of these attacks did not justify a full scale military invasion of the Gaza strip, or the mass destruction of infrastructure essential to life in the strip."
Candidate 3: "Israel similarly violated the ceasefire prior to 2008, and had unlawfully kidnapped and imprisoned hundreds of Palestinians. Furthermore, Israel's attack on Gaza was not an act of last resort. Israel could and should have tried to negotiate a truce with Hamas based on the following principle: an end to the Israeli siege on Gaza in exchange for an end to Hamas-led rocket attacks on Israel. This is the deal Hamas offered Israel before Operation Cast Lead was launched. Israel should have accepted Hamas’s offer and assessed whether Hamas’s intention to be bound by its terms was genuine before launching a military attack.(6) If an action isn't truly an act of last resort, it cannot be legitimately termed 'self-defense', and so is not justified. Hamas were prepared to enter into negotiations with Israel and it was prepared to discuss the more intricate details of the deal it had proposed. Its attempts to avoid conflict were committed and consistent enough to suggest that Gaza’s leaders were not engaged in diplomatic posturing or sabre rattling. Israel targeted more than just military targets, including UN warehouses holding medical and food supplies, UN schools, and hospitals. Its imprecise tactics and refusal to allow access of humanitarian workers show that it was not merely self-defense."

The long-term security of Israel rests in a stable peace agreement with the Palestinians, not in attempting to bludgeon Hamas into a truce 'on Israel's terms'. To the extent that Israel's large scale assault on Gaza eliminated the hopes of such an agreement, the attacks worsened Israel's long-term security.

A crucial step towards peace is to bring Hamas to the bargaining table. Israel's levelling of Gaza emboldened Hamas' message of resistance, and allowed Gazans to continue to rely on Hamas. As long as Israel continues to justify Arab and Palestinian anger through its disproportionate response, it is unlikely that enough trust can be established to reach a peace deal.

Even Israelis recognize that this assualt has created an even larger barrier to peace. “This policy [Operation Cast Lead] is not strengthening Israel,” noted Sari Bashi, the executive director of Gisha, an Israeli human rights group that works on Gaza issues. “The trauma that 1.5 million people have been undergoing in Gaza is going to have long-term effects for our ability to live together."(10)
