First, Turkey requested a couple of batteries of Patriot missiles to protect its border. Word leaked out that they were concerned that Syria, in one last spasm of violence before the fall of Assad, would launch missiles with chemical warheads at Free Syrian Army positions along the border with Turkey.

Now we have President Obama once again warning President Assad that any use of chemical weapons would be a  "red line" that, if crossed, would result in American intervention.

CNN:

The United States warned Syria in no uncertain terms Monday not to use chemical weapons amid intelligence reports indicating President Bashar al-Assad's regime could be preparing to take that step as it escalates its fight against rebel forces.

"I want to make it absolutely clear to Assad and those under his command -- the world is watching," President Barack Obama said during a speech at the National Defense University in Washington.

"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," he said.

Obama has previously warned that any use of chemical weapons by Syria in its civil war would be crossing a "red line" that would prompt a swift U.S. response.

Earlier on Monday, Secretary of State Hillary Clinton issued a similar warning.

"I'm not going to telegraph in any specifics what we would do in the event of credible evidence that the Assad regime has resorted to using chemical weapons against their own people," she said. "But suffice it to say, we are certainly planning to take action if that eventuality were to occur."

U.S. officials are concerned that with fighting closing in on Damascus, forcing the temporary closure of the airport there, the regime may be feeling desperate and toying with the idea that chemical weapons could finally crush the persistent rebellion.

"We believe that with the regime's grip on power loosening with its failure to put down the opposition through conventional means, we have an increased concern about the possibility of the regime taking the desperate act of using its chemical weapons," White House spokesman Jay Carney said Monday.

The Syrian Foreign Ministry denied that the country had any plans to use chemical weapons, state TV reported. Citing a source at the ministry, state TV said Syria has repeatedly stressed it will not use such weapons, if they exist, against its people no matter the circumstances.

But U.S. officials say "worrying signs" suggest otherwise.

Israel has also indicated they will act if Assad uses chemical weapons. They can't afford to wait and see if Assad will stop at using those weapons on his own people.

Perhaps even more worrisome is the possibility of a quick collapse by the Assad regime followed by a scramble to get control Syria's stockpile of WMD. Israel has also hinted that if that scenario occurs, they will move in to secure the weapons so that terrorists don't get their hands on them.

But the Israeli military moving in to an Arab country might set off Egypt and would certainly rile Iran. With the probability that Assad's fall is not far off, any end game for Syria will revolve around securing WMD - perhaps even from the Syrian opposition which has many terrorist and jihadist elements both political and military.