There has been a serious escalation in the pressure on Syrian President Bashar al-Assad after US president Barack Obama warned there would be "consequences" if chemical weapons were deployed in the civil war raging in that country.
The Syrian regime is reported to have large stockpiles of chemical weapons based on mustard gas, cyanide and sarin gas.
In the earlier stages of the conflict there were repeated calls for these stockpiles to be secured to prevent them falling into the hands of extremist groups, including al Qaeda and Hezbollah, which make up part of the opposition forces.
The government of Israel was particularly concerned about Hezbollah obtaining such weapons as they would have posed a serious threat from southern Lebanon during any future conflict.
That has changed somewhat in recent months as the Assad regime has suffered a series of major setbacks, including defections and desertions from the senior ranks of the military and political establishment.
The momentum of the battle appears to be currently in favour of the so-called rebel forces, with regime forces on the defensive and conceding major strategic and territorial positions.
President Obama warned President Assad this week that "The use of chemical weapons is and would be totally unacceptable, and if you make the tragic mistake of using these weapons there will be consequences and you will be held accountable."
Secretary of State Hillary Clinton also warned the regime against the temptation of using such weapons.
This is a red line for the United States. I am not going to telegraph in any specifics what we would do in the event of credible evidence that the Assad administration has resorted to using chemical weapons against their own people. But suffice it to say we are certainly planning to take action if that eventuality were to occur.
There are also reports that the military forces of Jordan, Turkey and Israel have been put on high alert at the prospect of direct intervention in Syria should chemical weapons be used.
This sets the stage for a dramatic escalation of the conflict should the regime in its desperation deploy these terrible weapons.
In this environment, the reckless recent suggestion by Australian Foreign Minister Bob Carr that President Assad be assassinated could hardly have come at a more sensitive time.