In foreign policy, Bashar al-Assad continued his father's hard-line policy towards Israel. He has repeatedly said that there will be no peace unless occupied land was returned "in full", and continues to support militant groups such as Hamas and Hezbollah, although he has floated the idea of talks on the Golan Heights.
His vocal opposition to the 2003 US-led invasion of Iraq, and the Syrian authorities' tacit support of Iraqi insurgent groups, also prompted anger in Washington, but it was popular in Syria and in the wider region.
Syria's already tense ties with the US soured in the wake of the February 2005 assassination of Lebanon's former Prime Minister, Rafik Hariri.
The finger of suspicion was immediately pointed at President Assad, his inner circle and the Syrian security services, which dominated Lebanon. Despite their denials of involvement, international outrage at the killing forced Syrian troops to withdraw from Lebanon that April, ending a 29-year military presence.
A UN tribunal earlier this year charged four suspects, all connected to Hezbollah, in connection with the killing of Hariri.
In recent years, Mr Assad has built close ties with Iran as well as Russia and China. Relations with Turkey and France had also improved until the uprising began.
The United States only resumed full diplomatic relations with Syria last January, although its ambassador has been a vocal critic of the crackdown on dissent and was briefly withdrawn after threats to his safety were made.
'External conspiracy'
When anti-government protests erupted in the southern city of Deraa in mid-March 2011, President Assad initially appeared to be unsure how to respond, but it was not long before only force was used to combat them.
In his first speech, two weeks after the first unrest, he insisted that questions of reform and economic grievances had been overshadowed by a small number of troublemakers and saboteurs who had sought to spread among Syrians, as part of an external conspiracy to undermine the country's stability and national unity.
Then in April - with the death toll at 200 - Mr Assad dismissed the cabinet and officially lifted the hated Emergency Law, which had been in place since 1963 and under which security forces detained and tortured people with impunity.
He also said there would be also be new legislation to dilute the monopoly of the Baath party, a new, modern press and media law, and a law which would regulate demonstrations, whereby protesters would be protected by police.
But days later, the crackdown against protesters was stepped up.
Over the next month, soldiers supported by tanks were sent into restive towns and cities, including Deraa, Baniyas, Homs, Hama and the suburbs of Damascus, to combat "armed criminal gangs". By mid-May, the death toll had reached 1,000.
Despite the security forces' concerted and ruthless efforts, and pledges by President Assad to free political prisoners and start a "national dialogue" on reform, the uprising continued unabated in almost every part of the country.
In August, with the death toll at 2,000, Mr Assad told state television that his government was in no danger of falling. He said the solution in Syria was a political one, but that violence should be dealt with firmly.
He also said opponents of the regime were increasingly resorting to violence, carrying out attacks on the military, the police and other security forces.
By early December the death toll had reached 4,000, Syria's security forces had lost control of large parts of the country and been accused by the UN of crimes against humanity, and sanctions were crippling the country's economy, but Mr Assad maintained a defiant tone in an interview with ABC News.
The president denied ordering the military to kill or be brutal in its crackdown on anti-government protesters, saying only a "crazy person" would kill his own people.
"There was no command, to kill or to be brutal," he said. "I don't own them, I am president, I don't own the country so they are not my forces."
"I did my best to protect the people, so I cannot feel guilty," he added.
"You feel sorry for the lives that [have] been lost. But you don't feel guilty - when you don't kill people."
Mr Assad also challenged the "false allegations" on which much of the media - and the UN Human Rights Commission - had based their conclusions about what was happening in Syria.