AFTER a year of increasingly murderous violence, Syria is hovering on the brink of outright civil war with the majority Sunni population coming under attack from government forces in the beleaguered city of Homs.

As heavy artillery shells continue to rain down on this largely industrial city, it is clear this is no ordinary bombardment aimed at quelling a rebellion, the version favoured by the government of President Bashar al-Assad.

The areas being targeted yesterday, Baba Amro and Bab Sebaa, are populated by Sunnis who bore the brunt of last week's estimated 400 casualties in the city. Violence also flared in Damascus with fighting reported within one mile of Abbaside Square, and gunmen targeted Brigadier-General Dr Isa al-Kholi, killing him as he left his home in the north of the city yesterday.

Another shocking incident occurred in the northern city of Aleppo on Friday. In two incidents, car bombs exploded outside the local headquarters of the Military Intelligence Directorate and the barracks of the Security Preservation forces, killing 28 people. No group has claimed responsibility for the attack. Because Aleppo has remained loyal to Assad, suspicion has fallen on the breakaway Free Syrian Army (FSA), composed largely of Sunni deserters from the government army but this has been strongly denied.

Brigadier-General Firas Abbas told reporters that security forces will not give in to violence. "These criminal acts carried out by these groups will not prevent us from continuing our efforts in order to crush terrorists in this city," he said.

While rival spokespersons argued about culpability, US intelligence sources hinted that the attacks could have been carried out by al-Qaeda in Iraq (AQI) which is attempting to reassert the influence of Ayman al-Zawahiri, the Egyptian-born extremist who assumed leadership of al-Qaeda after the assassination of Osama bin Laden last May. Not only is AQI a Sunni-based organisation but the car bombs were similar to those used in attacks in Afghanistan and Pakistan.

In an attempt to find a diplomatic solution following Russia's vetoing of an Arab League peace plan in the Security Council, the matter is now being passed to the UN General Assembly. The body has no legislative authority but carries considerable moral force and tomorrow will debate a Saudi Arabian resolution calling for an end to the violence and the appointment of a special UN envoy for Syria.

Diplomats believe the Saudi intervention is one of the last chances for a peaceful outcome to the bloody confrontation. On Friday, King Abdullah of Saudi Arabia made a surprisingly emotional plea for peace when he criticised the Russian veto and called for a solution. "These countries don't rule the world," he said in a televised speech. "The world is ruled by wisdom, fairness, morals and standing up to the aggressor. We are living in scary, scary days."

Syria Civil War:

Syrian against Syrian

To understand why the Syrian armed forces have unleashed such unparalleled violence against civilians is to get to the heart of how the country is ruled by the al-Assad dynasty. When Hafez al-Assad became president in 1971, he was largely successful in modernising the country and giving it much-needed political and economic security, but the reforms came at a price.

Under his direction, the security and intelligence services were expanded and became responsible for instituting widespread repression. All opponents of the regime were subject to immediate arrest and imprisonment without trial, using techniques which even won the admiration of the KGB – throughout his first years in office Assad used his contacts in Moscow to make Syria a client state of what was then the Soviet Union.

In this respect it helped that Assad was supported by religious minorities such as the Christians, Druze and, above all, the Alawites, a mystical grouping and part of the Shia sect. In a short time most of the senior posts in the government and the armed forces were Alawites, giving them an enormous incentive to cling to power through their allegiance to Assad.

The minority Sunnis were marginalised and any attempt to redress the balance was savagely punished. In 1982, the town of Hama was bombarded to quell opposition from the Sunni-dominated Muslim Brotherhood and up to 10,000 were killed. Following Hafez al-Assad's death in 2000, he was succeeded by his son Bashar and hopes were high that this London-trained ophthalmologist would be a reformer.

However, although there has been some liberalisation of the economy, it was a case of business as usual. Political opponents continued to be arrested and tortured an,d at the beginning of last year, when protests broke out in the border town of Deraa, demonstrators were crushed by army tanks and heavy artillery. Two key units are commanded by the president's brother Maher al-Assad and most of the senior officers are Alawites or Shias.

As the violence escalated, soldiers, mainly Sunnis, started deserting into southern Turkey to form the Free Syrian Army (FSA). Although they have only light weapons, they have become an important opposition and numbers are growing. In an attempt to excuse the violence being meted out to the population, Assad claims the FSA is a criminal group with links to al-Qaeda, but the truth is that he is desperate to crush the revolt and prevent it becoming a full-blown civil war. He and his cohorts are fighting for their lives.

Regional Politics:

Sunni against Shia

Throughout the "Arab Spring" in Tunisia, Egypt and Libya, there was never any likelihood there would be foreign military intervention. Despite calls for the creation of safe havens as were introduced to protect the Kurds in Iraq during the 1990s or the air power which helped to topple Muammar Gaddafi in Libya, the international community has held its fire.

Prompted by some skilful diplomacy by Turkey's Prime Minister Recep Tayyip Erdogan, the Arab League sent in a team of monitors at the end of last year but the killing continued unabated. Sanctions have been introduced by the European Union but all attempts by the UN Security Council to follow suit have been vetoed by Russia. The only punishment of any note came from the Arab League which has suspended Syria from its membership.

However, the absence of direct action does not mean the world is doing nothing. One of the most vocal critics of the Assad regime has been the been the hugely influential Gulf kingdom of Qatar which closed its embassy in Damascus last summer and has been sending arms to the FSA.

Today, it will chair a meeting of the Gulf Co-operation Council in Cairo to discuss further action. As one of the wealthiest of the Gulf states, Qatar is well placed to exert pressure on Syria and, as a Sunni state, it also has a vested interest in protecting its co-religionists. After years of uneasy relations with Saudi Arabia, Qatar has mended fences and the emergence of a Saudi-Qatari alliance could be the main means of protecting the Sunni population in Syria.

While an Arab solution remains the best option, it opens the possibility of confrontation with Iran, Syria's main backer in the region and a leading Shia power. Senior commanders from Iran's Quds Brigade, a wing of the Iranian Islamic Revolutionary Guards Corps, have been advising Assad and their presence could be the pretext for Saudi Arabia and Qatar to increase military support. There is a great danger that Syria could become a proxy battleground for the rival religious ideologies and their main supporters: Iran for the Shias and Saudi Arabia and Qatar for the Sunnis.

Cold War Revisited:

Russia against USA

Throughout the Cold War Syria was an important client state of the Soviet Union which saw the country as a check on US support for Israel. As a result, Syria benefited from Soviet technology and its armed forces were equipped with Soviet weapons systems. This policy was encouraged by President Hafez al-Assad and has been continued by his son.

When Russian Foreign Minister Sergei Lavrov was asked about the morality of the policy during a visit to Damascus last week, he said selling arms was not illegal. In part Russian policy is still guided by the need to gain leverage in Syria through the sale of weapons and technology, but Lavrov also senses a diplomatic opportunity. Russia vetoed the Arab League peace proposal in the UN Security Council because it would have meant Assad standing down, but they also knew the move would spike US policy in the Middle East.

Although then President Vladimir Putin supported the US-led invasion of Iraq in 2003, Russia remains suspicious of regime change in the Middle East and unhappy about its use in Syria. At the same time, it offers support to neighbouring Iran by supplying nuclear technology and opposing sanctions in the UN.

It also senses an opportunity to create problems for the US and its Sunni allies, Saudi Arabia and Qatar. Last week, Washington lawmakers introduced a resolution in Congress calling for the US to give "substantial material and technical" to the FSA. While this carries no political weight, it will put further pressure on President Barack Obama to adopt a more rigorous policy by imposing sanctions on the Assad regime or providing "robust humanitarian assistance" to Syria.

In an election year, Obama is keen to avoid unnecessary foreign complications but, as other countries become involved in the current confrontation, there is a real fear that Syria could provide the spark to an already volatile Middle East.

"There is a risk it could become a proxy conflict. It is headed in that direction," says Andrew Tabler of the Washington Institute for Near East Policy.

"I think you will see now different countries in the region betting on the FSA. Weapons have been coming in from Lebanon. You will now see more from Turkey, Iraq or Russia. Everyone will start to operate in this environment."