Updated April 07, 2017 21:00:50

Photo: According to US media, the strikes were carefully targeted to avoid hitting chemical weapons at the base. (AP: US Navy)

The US cruise missile strikes on Shayrat airbase raise troubling questions for the international system, the US and allies including Australia.

For nearly three years they have been aware of evidence that Syrian President Bashar al-Assad may not have declared all of his chemical weapons stockpiles, and these strikes have highlighted the dilemma about what to do now.

The missile attack came after years of heated debate and deliberation in Washington over intervention in Syria's bloody civil war.

Remember the horrors of the gas attacks east of Damascus in 2013?

Then, as now, the Syrian Government denied responsibility and blamed the rebels.

But under threat of airstrikes by the Obama administration, Syria confirmed the enormous stockpile of chemical weapons it had amassed in a secret program and agreed to dismantle the program and have the chemicals destroyed.

Officials from the Organisation for the Prohibition of Chemical Weapons then embarked on a dangerous and difficult mission to do just that and announced they had successfully destroyed all declared stockpiles.

But from early 2014, officials at the OPCW's headquarters, including representatives from the US, Australia and other allies, became aware of evidence that Syria had not declared all of its weapons program.

There were tell-tale chemical traces where they shouldn't be, and other sites were implicated.

As it has at the UN Security Council, Syria's ally Russia blocked substantial action and the Syrians stonewalled with incomplete and inconsistent answers. It's been a little-noticed but alarming dispute.

What will be done to investigate?

Now the US alleges Syria still has chemical weapons and used them. The Syrians and the Russians deny they exist.

So what will be done to investigate this claim?

US media reports quote Government officials saying the strikes were carefully targeted to avoid hitting chemical weapons stored at the base.

In Syria there is widespread suffering, dying and desperation, but exposing the horror to the public isn't sparking any change. Philip Williams investigates.

Can there be a repeat of the inspections that followed the 2013 attack?

Do declarations from US officials that this was a "one-off" strike provide leverage for further inspections, or do they undermine that prospect?

As I write this in Beirut, I am less than 150 kilometres from that base, which is less then 40 kilometres from Lebanon's border — just one example of how tightly packed this region is, and how sensitive it is to a strategic threat like chemical weapons and further escalation of the conflict in Syria

If, as the Russians and Syrians claim, rebel groups had these weapons, what do they propose to do about it?

And if, as US President Donald Trump said, the weapons belonged to Syria and the strikes were designed to deter the spread and use of chemical weapons, what now?

Is the follow-on message that it is OK for Mr Assad to possess these weapons, as the US alleges, as long as he doesn't use them?

The chemical weapons incident this week threw the region back into an especially volatile and uncertain zone, bringing doubts about Syria's declarations to a head, and the US strikes on Shayrat air base have not resolved those issues.

Topics: unrest-conflict-and-war, world-politics, syrian-arab-republic, united-states

First posted April 07, 2017 17:55:57