The leaders of the western world are wringing their hands in despair at the sight of the horrors inflicted on Gaza (Gaza crisis, 16 January). The UN general secretary, the French president and others are holding intensive discussions with some of the leaders of the Middle East in an attempt to put an end to the carnage in Gaza. Word, words, words.

Meanwhile, hundreds of Palestinian civilians get killed, thousands are bleeding to death, tens of thousands are uprooted and wandering in vain in search of some shelter to protect them. The Israeli army bombs hospitals and Unrwa relief centres, and, defying international convention, it uses white phosphorus bombs against civilians. "What else can we do?" these leaders keep asking. Well, here is what you can do: move from words to deeds. Only immediate, decisive and strict sanctions against the state of Israel and its limitless aggression will make it realise that there's a limit.

We, as Israeli citizens, raise our voices to call on EU leaders: use sanctions against Israel's brutal policies and join the active protests of Bolivia and Venezuela. We appeal to the citizens of Europe: please attend to the Palestinian Human Rights Organisation's call, supported by more than 540 Israeli citizens (www.freegaza.org/en/home/): boycott Israeli goods and Israeli institutions; follow resolutions such as those made by the cities of Athens, Birmingham and Cambridge (US). This is the only road left. Help us all, please!

Prof Yoram Carmeli Haifa University

Prof Rachel Giora Tel Aviv University

Dr Anat Matar Tel Aviv University

Jonathan Pollak

Dr Kobi Snitz Technion - Israel Institute of Technology

And 17 other Israeli citizens

The distinguished academics introduce their letter (16 January) by stating "... a war that Israel has been waging against the people of Palestine for more than 60 years ...". May I remind the writers that when the state of Israel was established - by the UN, in 1948 - it was five Arab armies and all the Palestinian militias who invaded Israel and not the reverse. May I also remind them that Israel only obtained the territories in 1967 - after having to fight a third war for survival. And that within a week of winning that war - and occupying the territories - Israel offered to return them in exchange for peace, an offer echoed in UN resolution 242 (and delivered with the return of lands to Egypt in 1979). The emphatic Arab response came at the conference in Khartoum in 1968, with the famous three nos: no recognition of the state of Israel, no negotiation with Israel and no peace with Israel. The Palestinians - and many Arab states - have sustained that belligerency ever since and in every forum: military, economic and diplomatic.

Joshua Rowe

Manchester

• This article was amended on Sunday 18 January 2009 to correct a production error that removed the last sentence from the second letter and appended it to the end of the first letter. This has been corrected.