Wars that merely repel an aggression can be likened to kicking a robber out of the house and returning to sleep. The robber will likely come back, and so will the repelled enemy. Societies have three approaches to dealing with robbers: prevention, correction, and discouragement.
Prevention is dubiously effective; felons show a high rate of repeated commission of offense. After years in jail, criminals lose a connection to peaceful, law-abiding life. Jails prevent the criminals for only as long as the criminals stay in jails. The foreign policy equivalent to prevention is sanctions. America’s sanctions against Iraq after expelling it from Kuwait were fairly effective in crippling the Iraqi military capability. Israeli sanctions against Hamas-ruled Gaza suitable damaged Palestinian society, but not Hamas. Sanctions are inefficient against micro-targets that can be re-supplied by smuggling and donations. Sanctions, like jail term, end one day, leaving an embittered enemy alive.
Correction is rarely practiced with criminals for its obvious futility, but cowards and idealists love correcting enemy nations. A common idea is that a nation forcibly given affluence and democratic institutions will become peaceful. The failure of that approach can be witnessed in Iraq and Gaza.
Discouragement is the only consistently effective strategy of curtailing crime. Discouragement is “an eye for an eye” strategy, aimed at inflicting enough suffering on perpetrators to make their trade non-feasible. Discouragement consists of corporal punishment or mutilation, extremely harsh jail conditions designed to break criminals physically and morally (a politically correct mode of mutilation), or – on the international arena – of the extreme destruction of the enemy country. The utmost discouragement is execution for criminals and ethnic cleansing for nations. The Torah doesn’t hesitate to prescribe capital punishment for heinous criminals and annihilation for sworn enemies, while Machiavelli asserts that ethnic cleansing is the only reliable seal on a victory.
Israel cannot punish Hamas; the death of a few dozen, even a few hundred members is no blow to Hamas, but will only reinforce its military credentials. After Hamas engages Israel for a week or two, the group will confirm itself a formidable guerrilla force and attract more donations. Hamas doesn’t even care about losing the support of Palestinian voters; in the short term, bullets overcome ballots.
Israel has two strategic alternatives. One is tolerating the violence for years or decades to come; the violence could eventually subside as the former enemies grow used to each other or, more likely, the determined Arab enemy will be sinking its teeth into Israeli defenses. Israel voices no claim on Gaza; Hamas demands the entire Israel. The balance of will is on Hamas’ side; Arabs’ constant aggression erodes the Israeli passive defense and causes incessant concessions. Another alternative means recalls the Torah and preferably Machiavelli as well. The evacuation of Sderot must be repaid with the evacuation of Gaza. Evict all the Arabs to Jordan.


"The wars which merely repel an aggression"
I used to explain this to my Israeli friends by telling them that Israel has never fought any wars. Israel only defends, which is why there has been a major assault on Israel every decade, basically.
Until Israel starts fighting wars, which include raining hell on enemy CITIES, the arab population will not be discouraged from trying to exterminate Israel. Even if the Arabs have nothing more than a 1% chance of winning, if given enough opportunities, they will eventually be triumphant (as almost happened in 1973).
The US and Allies killed almost 10% of the German population in WWII, and the US killed 4% of the Japanese population. Those are the sorts of numbers (higher for arabs, though - for cultural reasons) that Israel is going to have contend with some day, if they want to ever have any chance at actual peace.
At least 200,000 Lebanese Shiites should have died in the Lebanese "war" last summer, and no less than 100,000 Gazans should have been sent to virgin-land. But Israel doesn't have the guts to do that … which means that, eventually, Israel will lose ….
If Israel cannot bring itself to kill the number required to actually start affecting the arab desire to fight, who on Earth believes that Israel's nuclear deterrent scares anyone? (P.S. The US has the exact same problem, now)
just by surviving continuous assaults, Israel will never find peace. Arab money,oil and determination have bought friends in England among University and jounalists. Time is not on Israel'sside.