I have Palestinian colleagues in Gaza. They are democrats and human rights defenders who are critics of the Hamas regime and opponents of terror attacks on Israel. Some have been detained and tortured by the Islamists.

Together with much of the Gaza population, for seven days they cowered in fear of Israeli bombardment. Why were they - and so many other innocents - terrorised by the Jewish state on account of the crimes of Islamist extremists?

My heart goes out to all Israeli and Palestinian civilians who were caught in the cross-fire. The Gaza conflict has affected too many innocents on both sides.

Israel launched more than 1,500 airstrikes on Gaza, while Islamists fired over 1,000 rockets into Israel. At least 160 Palestinians were killed, including dozens of civilians, and five Israelis died too. A rather one-sided death toll. Nevertheless, I mourn all these deaths.

The traumatised victims include not only civilians who've lost loved ones or been injured but also everyone (millions of Palestinians and Israelis) who lived in daily fear of attack. The psychological and emotional strain was immense. No one should have to endure this unrelenting trauma - a trauma to which successive generations have been subjected for decades.

This is why it is so important to find a lasting peaceful solution that can ensure security for both Jews and Arabs.

While the Egyptian-brokered ceasefire is welcome, it will only last if the legitimate grievances of the Palestinian people are remedied. Similar ceasefires have failed in the past precisely because of a lack of progress towards a negotiated settlement that is fair to the Palestinians.

The Israeli seizure and occupation of Palestinian land, and the denial of a Palestinian state, are the root cause of the on-going conflict and the last week's flare up in Gaza. There will be no enduring peace without first securing justice for the people of Palestine.

A genuine injustice is what gives the Palestinian fanatics influence. While the injustice exists, they will continue to exploit it. Remedy the injustice and they will be sidelined.

This is a viewpoint shared by many Israelis and by many in the Jewish Diaspora. They reject the hardline stance of the current Israeli government. They, too, recognise that justice is a precondition for peace.

Most Palestinians would accept peace with Israel if they secured a just settlement.

The Palestinian people have a right to their own homeland - just like Jews. It is time to take serious steps to secure peace, justice, equality and security for all - Palestinians and Israelis - by means of two co-existing states based on the 1967 borders.

To this end, I have joined with more than 1.5 million other people (so far) to sign the Avaaz petition here.

It urges world leaders to press for an end to the Israeli occupation of Palestinian land, and for the recognition of an independent Palestinian state, as the most effective way to break the log jam in the stalled peace process.

While rocket attacks on Jewish civilians are absolutely wrong, Israel's escalation in Gaza risked sparking a major regional conflict, possibly involving Iran and its proxy, Hezbollah. This is not in the interest of the people of Israel, Palestine or the wider region.

Palestinians are justified to non-violently resist Israel's seizure of land, demolition of houses, destruction of crops and the killing of civilians. The divisive, sectarian wall and the building of illegal Jewish settlements on the West Bank undermines the prospects for peace and plays into the hands of Islamist extremists.

Israel's oppression of the Palestinians does not justify Islamists firing rockets into Jewish civilian areas. Nor do rocket attacks justify Israel's bombardment of Gaza and the consequent civilian deaths.

Israeli actions are tantamount to the terrorisation and collective punishment of the Gaza population, which is illegal under international law. The same is true of attacks on Israeli civilians by Hamas, Islamic Jihad and other Islamist terror groups.

The deliberate or reckless killing civilians is a war crime - whoever does it, for whatever reason. The human rights of both Israelis and Palestinians must be protected.

The cycle of attack and counter-attack, revenge and pay-back, is immoral and futile. Neither side gains. Insecurity is compounded and the seeds of further conflict are sown.

The Hamas regime in Gaza is guilty of serious human rights abuses against its own Palestinian citizens, including unfair trials, torture and executions.

See, as one example, the Human Rights Watch report: Abusive System: Failures of Criminal Justice in Gaza, October 2012.

Hamas has also sanctioned rocket attacks on Israeli civilians.

It is truly shocking the way some western pro-Palestinian, anti-war and left-wing groups variously defend or excuse Hamas. As well as being anti-Semitic, Hamas is an authoritarian, reactionary movement.

While people are right to be critical of Israel's stance towards the Palestinians, it is also important to defend Jewish people against Islamists and other anti-Semites.

Human rights are universal and indivisible. They apply to everyone, even perceived enemies. The lust for vengeance is self-defeating.

An-eye-for-an-eye leaves everyone blind.

Peter Tatchell is Director, Peter Tatchell Foundation: www.PeterTatchellFoundation.org