This despairing "message to the world" from the people of Zabadani, a hill town near the Lebanese border that has been under siege since 2012, was posted on Twitter on August 15 as the seven-week battle between the Syrian army, backed by Hezbollah fighters, and opposition rebel groups intensified.

Zabadani citizens have endured more than 600 barrel bombs - huge, improvised explosives dropped from Syrian air force helicopters - in the two months since June, in a wave of terror from the sky that was met with rockets and heavy mortars from rebel groups.

A day later and 60 kilometres away, a new horror was unfolding as multiple Syrian government air strikes hit a busy Sunday market in the rebel-held town of Douma, killing 112 and injuring at least 550 others in one of the deadliest attacks since the Syrian crisis began in 2011.

Bodies and body parts lay strewn across the street. Most of the dead and injured were civilians. Some were killed, Human Rights Watch says, when they came under attack from Syrian government forces in the local cemetery as they tried to bury their loved ones.

A doctor described row after row of injured lying on the ground in critical condition at the local hospital, medical staff and patients swimming in a sea of blood.

And yet these were not the first midday attacks on busy markets in the Eastern Ghouta area, where Douma is situated, just 14 kilometres from the centre of Damascus.

Amnesty International has documented several large-scale attacks in Eastern Ghouta between January and June this year, including air strikes on a market in Hamouria on January 25 that killed more than 40 civilians and another attack on the market in Kafr Batna on February 5 in which 45 civilians were killed.

An analysis of data gathered by the Syrian Network of Human Rights, a London-based organisation that analyses on-the-ground reports following attacks, found three-quarters of all civilian deaths in the conflict were caused by Syrian regime warplanes as well as their indiscriminate use of barrel bombs. No other armed group, including Islamic State, has warplanes or helicopters, it reported.

And yet in Australia - mirroring the position of the United States and Britain - the discussion is centred firmly on military action to contain and defeat IS and the push to expand Australia's role in the campaign outside Iraq and into Syria.

"They're raping, they're murdering, they are pillaging and we need to stop the foreign fighter flow to the caliphate in Syria," Liberal backbencher and chair of the parliamentary joint committee on intelligence and security Dan Tehan told ABC television.

Prime Minister Tony Abbott confirmed the United States had approached Australia about escalating its operations into Syria, where several international coalition partners are already operating.

Adopting the "IS first" approach of the United States, there appears to be no room in Australia for discussion about the war crimes the Assad regime is committing against its people.

No acknowledgement that in this four-year-long civil war in which at least 250,000 people have been killed, 7.6 million are internally displaced and 4 million Syrians have been forced to flee their country, IS is just one of several armed groups terrorising civilians.

"The war against the Islamic State is one war amongst many that are unfolding in Iraq and Syria today and the attempt to delink one conflict from another is very counterproductive," says Julien Barnes-Dacey, a senior fellow at the European Council on Foreign Relation's Middle East & North Africa program.

"So long as you have a civil war raging between the Assad regime and the opposition, it is very hard to find common focus not just amongst Syrians but also amongst the key regional actors and international players in terms of fighting Islamic State."

Add to that, "there is a deep sense of grievance amongst many Syrians that the West seems to have abandoned them by focusing so singularly on fighting the Islamic State even as the regime continues its brutality".

It is a narrative, he warns, that causes local support to move towards jihadists.

In reality, the main players are trying to exploit the existence of the IS to further their own ends, leading to deep concerns in the West that if the Assad regime were to fall it would create a vacuum that IS is perfectly positioned to exploit, Barnes-Dacey says.

There is very limited appetite for an expansion of Britain's military operations against IS in Iraq into Syria, he says.

"The UK government has been pushing this most forcefully, saying they want to start bombing in Syria, but that is more about wanting to provide assistance to the US government … in order to preserve their privileged position with the US."

There has been a strong degree of pushback from Conservative and Labour MPs to encourage regional states to push domestic actors towards some kind of settlement, he says.

"There is a thin line between using military force constructively and leaning too heavily on it in a manner that can prove counterproductive," Barnes-Dacey says.

"The anger provoked by civilian casualties and the lack of any response to Assad's brutality feeds on a dangerous trajectory in terms of where the Sunni world is headed, and its relations with the West."

There is no doubt that Western governments have a credibility problem following the military interventions in Iraq, Afghanistan and Libya, says James de Waal, a former British diplomat and now a senior consulting fellow in the International Security Department at Chatham House in London.

"These governments tend to be better at getting rid of a threat or a risk or someone: Gaddafi, Saddam Hussein in Iraq or the Taliban, than actually building peace afterwards," he told Fairfax Media.

"In Syria and Iraq there is a lot of the rhetoric about defeating [Islamic State] rather than what will happen afterwards. But if the aim of your military action is unclear, then that makes this all very risky."

For Canberra, he notes, the aim may well be to make a useful contribution to resolving the situation in Syria, although it is just as likely to be driven by a desire to maintain its strategic relationship with Washington or bolstering its international profile.

"Those are well established reasons for using force … however these days it is far more difficult to convince a sceptical public that using force will help you achieve those aims."

The degree to which the interests of the Australian, British or US governments are in line with the interests of the Syrian people is unclear, he says.

"When the coalition governments are talking about their military activities they are much better at explaining the inputs - how many soldiers, how many planes, how many bombs they've dropped, how many people they have trained," De Waal explains.

"They are much less effective at being able to describe what has been the outcome or impact of all of that. I am looking for some credible link between the input and the output."

He is doubtful that Western militaries have learned the lessons of their failures Iraq and Afghanistan and questions whether there is a genuine role for countries like Britain or Australia in an international military coalition in the Middle East.

In the meantime, human rights groups continue to push for the United Nations Security Council to enforce resolution 2139, which calls on the Assad regime to stop its attacks against civilians and end the shelling and aerial bombardment.

"UN Security Council members, including Russia, which has shielded the Syrian government from sanctions and accountability, should take immediate steps to enforce that demand," Human Rights Watch said on Thursday.

"In addition to an arms embargo, the Security Council should apply the same level of scrutiny it has put in place for chemical attacks to all indiscriminate attacks by monitoring these attacks, attributing responsibility for them, and sanctioning those responsible. The Security Council should also refer the situation in Syria to the International Criminal Court."

Pieter Wezeman is a senior researcher in the arms and military expenditure program at the Stockholm International Peace Research Institute.

He says there is no arms embargo on weapons supply against Syria, either at the European Union or United Nations level.

In February 2013 the EU attempted to renew its arms embargo against Syria that had been in place since May 2011, yet after a lack of agreement over a proposal from France and Britain to amend the embargo to provide the option of supplying arms to opposition forces, the ban expired, Wezeman says.

"The arms embargo or any restrictions on arms supplies to actors in Syria has been undermined and weapons have come from Iraq, where there was no embargo."

As militants from Islamic State stormed across the Syrian border into Iraq and took control of the city of Mosul, "everyone agreed they had to be stopped", he says.

One way of stopping their advance was to arm Kurdish groups in the area, he says.

"Everyone agreed, even in Sweden, that arming the Kurds was a necessary emergency action, but it is not a long-term way of resolving the conflict and it is a risky step to take.

"How do you prevent a large arsenal being built up … getting out of control and either the Kurds eventually fighting amongst themselves or fighting against Iraqi authorities, or those weapons falling into other hands?"

In the meantime, the United Nations via its special envoy, Staffan de Mistura, has set out another plan for a political transition of power in Syria, urging a "Syrian-led" political transition without formally calling for Assad to step down.

Even as the Syrian regime continues to lose ground in Syria, where it controls around one-third of the territory, countries such as Australia, Britain and the US are pushing to fight along another front in the Syrian war.

Assad and his atrocities don't even rate a mention. All eyes are on the Islamic State group and its social-media driven horrors.