Yitzhak Shamir: Member of the Stern Gang who became a hawkish Prime Minister of Israel

Yitzhak Shamir was a revolutionary who grew old but never mellowed. Into his eighties he retained an intensity of vision, an inflexible commitment to the consolidation of Jewish sovereignty in the whole “Land of Israel” west of the Jordan, and a ruthlessness shading into indifference.

He was as secretive and wary when he was Israel's Prime Minister in the 1980s and early '90s as he had been when he was a leader of the fanatical Stern Gang in its struggle against British rule four decades earlier. Shamir despised the gregarious showmanship and adventurous mind, the admiration for generals and professors, of Menachem Begin, another underground warrior of the right who preceded him in the premiership.

Shamir, a short, stubby man with the physique of a Graeco-Roman wrestler, summed up his credo as: "Be inconspicuous, quiet. Walk in the shade. Be a little stooped, a little shabby. Never preen or show off." He had no trouble living up to that. He claimed, more plausibly than most politicians, to have no personal ambition.

"Shamir took decisions," one of his Stern gang once told me, "but he was not impulsive. You never saw his enthusiasm, but you always saw his thinking, his being careful about everything. Some of our people thought he was too slow taking decisions, but everyone felt you could rely on him."

One of his Likud Party ministers echoed this assessment: "Shamir is the most cautious, unadventurous prime minister Israel has ever had, His motto is don't do anything that will get you into trouble. He doesn't take risks that would get us involved in war, but the other side is that he doesn't take risks for peace."

As a Likud MP, he opposed Menachem Begin's Camp David peace agreement with Egypt in 1978. As Foreign Minister three years later he claimed (in memoirs published 12 years afterwards) to have harboured doubts about Israel's invasion of Lebanon, though there is no record of any criticism at the time. When a more junior minister appealed to him to stop Israel's Lebanese militia allies slaughtering unarmed Palestinians in the Sabra and Shatilla refugee camps, Shamir replied, "I hear you," and did nothing.

As Prime Minister in a national-unity government he vetoed a 1987 deal that his insubordinate Labour Foreign Minister, Shimon Peres, had negotiated secretly in London with King Hussein (it threatened to revive Jordan's claims to the West Bank it had lost in the 1967 war).

But he had the strength and wisdom in 1991 to resist demands from the military and the public to retaliate for Saddam Hussein's Scud missile attacks on Tel Aviv. It was, he confided, one of the most difficult decisions he had ever taken. He recognised that if Israel had entered the Gulf War it would have destroyed the US-led coalition.

The nearest Shamir came to taking an initiative for peace was the 1991 Madrid conference, which opened a way for negotiations with all of Israel's immediate neighbours, including the Palestine Liberation Organisation under the transparent camouflage of a joint Jordanian-Palestinian delegation. The Prime Minister led the Israeli team to the opening session, but admitted after losing the 1992 election to Yitzhak Rabin that he would have dragged out the Palestinian autonomy negotiations for another 10 years while cementing the Jewish presence in the West Bank and Gaza Strip.

For Shamir, the occupied territories were an exclusively Jewish patrimony. The PLO, as he told a Likud rally, were nothing but "foreigners, terrorists, brutal, savage, alien invaders."

Yitzhak Shamir was born Yitzhak Yezernitsky in 1915 in the small Polish border town of Rujenoy. His family, who owned a modest leather factory, were ardent Zionists. Shamir's mother and a sister were killed in the gas chambers of Treblinka; his father and a second sister's family were murdered by Christian neighbours to whom they had turned for shelter. It was a lesson Shamir never forgot: the Jews could trust no one but themselves.

He was an uncompromising fighter from the day he joined Ze'ev Jabotinsky's ultra-nationalist Betar youth movement. He moved to Palestine in 1935 and was recruited to Betar's military wing, the Irgun Zvai Leumi, two years later. Unlike Begin – a commissar rather than a combatant – the young Shamir took part in retaliatory raids against Arab rioters.

After the Irgun split in 1940, Shamir followed Avraham Stern into a splinter group that rejected Jabotinsky's call for a truce in the anti-British struggle so long as Britain was fighting Nazi Germany. Stern was shot dead by the British police in 1942 and Shamir was one of a troika that took command; he was in charge of organisation. He was arrested twice, in 1941 and 1946, and escaped twice, the second time from a prison camp in Eritrea.

In 1944 Shamir sent two young fighters to Cairo to assassinate Lord Moyne, Winston Churchill's resident minister in the Middle East. In a 1996 Israeli television reconstruction of the murder, Shamir was still snarling with hatred for Moyne, who he accused in his memoirs of "extreme opposition to Zionism and negative feelings about the Jews", and was still celebrating the deed.

Years after the event he reflected: "A man who goes forth to take the life of another, whom he does not know, must believe only one thing – that by his act he will change the course of history." In fact, the Moyne assassination had the opposite effect to that intended, sharpening divisions within the Jewish resistance and alienating the pro-Zionist Churchill.

Shamir was also one of the leadership team that authorised the assassination of the United Nations mediator, Count Folke Bernadotte, in Jerusalem in 1948. Within the Stern Gang, Shamir ordered the killing of Eliahu Giladi, a comrade who had escaped with him from British custody. Giladi, whom Shamir described as a reckless fanatic, was plotting to kill the mainstream Zionist leader David Ben-Gurion for "betraying" the Jewish cause. "Giladi," Shamir wrote, "had become far too dangerous to the movement."

Unlike Begin, who commanded the Irgun, Shamir did not rush into politics after Israel gained its independence in 1948. He drifted into private business, for which he had neither taste nor talent, then went back for 10 years into the cloak-and-dagger world as a senior officer in the Mossad overseas secret service. Ian Black and Benny Morris wrote in Israel's Secret Wars that Shamir "ran some ad hoc operations, usually involving assassinations." His main targets were German scientists designing rockets for Egypt. One of Shamir's favourite devices was the letter bomb. One packet, mailed from Hamburg, killed five Egyptians.

After returning to Israel in 1965 he joined Begin's Herut, a precursor of the Likud. He was first elected to the Knesset, Israel's parliament, in 1973 and was appointed Speaker after the Likud victory of 1977. Three years later he was promoted to Foreign Minister, By the time the ailing Begin faded away in 1983, Shamir was his natural successor. "He gives the impression of not being well educated," an old Mossad associate said at the time, "but it doesn't pay to underestimate him. He is self-educated, with a good, logical mind."

He served as Prime Minister from 1983-84 and 1986-92, resigning the leadership after losing the 1992 election. He stayed on as a backbench MP until 1996. Not long after retirement he was diagnosed with Alzheimer's disease, and he had spent the last few years in a nursing home in Tel Aviv.

His wife Shulamit, who had been his runner in the Stern Gang, once told an interviewer, "He takes his work to bed with him, eats with it, lives with it 24 hours a day." It was not clear whether she was boasting or complaining.

Yitzhak Yezernitsky (Yitzhak Shamir), politician: born Rujenoy, Poland (now Belarus) 15 October 1915; married 1944 Shulamit (died 2011; one son, one daughter); died Herzliya, Israel 30 June 2012.

Eric Silver died in 2008. This obituary has been updated.