By former BBC Middle East Correspondent Gerald Butt

A Syria - or a Middle East - without President Hafez al-Assad would be hard to imagine.

But recently there have been signs that the Syrian president, approaching 70 and reportedly in failing health, has become aware of his mortality.

The master tactician, who has been president of Syria since 1971, has been preparing the ground for his son Bashar to take over.

President Assad is also hoping that he can strike a deal with Israel's Prime Minister Ehud Barak.

The Syrian leader is prepared to make peace with his old enemy provided the Israelis withdraw from the Golan Heights, occupied in the 1967 Middle East war.

Patient and calculating

It is an opportunity that Mr Assad has been awaiting a long time, but patience has never been a problem for the Syrian president.

If, in the end, he considers that the deal offered on the Golan is not satisfactory, he will go on waiting.

Always patient, calculating and with his eye fixed unwaveringly and ruthlessly on his objectives. These are the hallmarks of the Assad presidency.

Military roots

Hafez al-Assad comes from the minority Alawite community in Syria - an offshoot of the Shi'ite sect of Islam.

He was born in 1930 in a village close to the port city of Latakia.

His career before becoming president was entirely in the military. He became an air force pilot, training in Egypt and the former Soviet Union.

In the 1960s, Mr Assad became involved in politics, as a prominent member of the Ba'ath Arab Socialist party.

At this time, Syria was wracked by political instability, with one coup succeeding another.

Mr Assad, who had been promoted to the rank of major general, was appointed defence minister in 1966.

By the end of the decade he had consolidated his political and military power and was ready to make a strike for the highest office in the land.

Power base

In November 1970, Mr Assad led a peaceful coup, and, in a foretaste of his style of leadership, arrested and quietly imprisoned his political opponents.

In the decades since becoming president and overseeing an unprecedented era of stability in Syria, he has encouraged public manifestations of support for his dictatorial rule and the Ba'ath party.

But he has continued to remain personally aloof and, for the most part, out of sight.

His preference for privacy has camouflaged a number of key ambitions that he has pursued single-mindedly since coming to power.

The first has been to stay in power - no matter what the cost.

So, for example, when he was challenged by Sunni Muslim extremists in the city of Hama in February 1982, he sent in the army. At least 10,000 people were killed, and large areas of the city flattened.

Another goal has been to regain control of the Golan Heights without making concessions to Israel - and to ensure that his second son Bashar keeps the Assad clan in power.

His eldest and favourite son, Basil, was killed in a car crash five years ago.

Lebanon goals achieved

While these last ambitions are receiving Mr Assad's attention at present, another - to secure Syrian control of Lebanon - has been achieved.

And it happened in a way that showed the Syrian president at his shrewdest.

First, he sent his army into Lebanon early in the civil war there to help the Christians in their conflict with the Muslims. But when the Christians later tried to form a pact with Israel, the Syrian army was ordered to switch sides.

In the end, with a fiercely anti-Syrian Lebanese general occupying the presidential palace in Beirut, Mr Assad saw the opportunity he had long been waiting for.

It was 1990, and the West was building a military alliance to challenge the Iraqi occupation of Kuwait.

To give credibility to the force, the West needed Syrian support. They got it, but in return he got a green light to allow Syrian jets to attack the presidential palace in Beirut, leaving the Christians defeated and the reins of power in Lebanon firmly in Mr Assad's hands.

Ignored at peril

The Syrian leader has been as ruthless in his dealings with the Americans as with the Palestinians and other groups in the Middle East.

It is assumed, for example, that Syria had a hand in the bombing of the US marine barracks in Beirut in 1983 and in other attacks on American targets.

But much as critics of President Assad, in the US or elsewhere, may abhor his style of leadership or mock the pretence of democracy in his country, they have been forced to learn one lesson: when entering the Middle Eastern political arena, you ignore the Syria of Hafez al-Assad at your peril.