LATEST: The CBS/AP 15 June 2012 confirms that a Russian ship is underway to Syria with soldiers and weapons - probably to protect Tartus. DEBKAfile 17 June 2012: Putin and Obama are set to dicuss Syria at the G20 meeting on 17 and 18 June in Mexico, as Russia is flying in anti -aircraft and antiship missiles to Syria at the same time as a fleet of Russian warships is heading  to Tartus.

DEBKAfile 16 June 2012 (Israeli intelligence outlet): US official sources, June 16,  about planned US military operations in the war-torn country:
The intervention will happen. It is not a question of ‘if’ but ‘when.’The White House is close to deciding on the format of its military operation in Syria. Some sources are defining it as “Libya lite” – that is, a reduced-scale version of the no-fly zone imposed on Libya two years ago and the direct air and other strikes which toppled the Qaddafi regime.
Following reports of approaching US military intervention in Syria and a Russian marine contingent heading for Tartus port, the UN observer mission in Syria has suspended patrols.

DEBKAfile 15 June 2015A contingent of Russian special forces is on its way to Syria to guard the Russian navy’s deep-water port at the Syria’s Mediterranean coastal town of Tartus, Pentagon officials informed US NBC TV Friday, June 15. They are coming by ship. According to Debkafile’s sources, the contingent is made up of naval marines and is due to land in Syria in the coming hours. See here

In a separate and earlier announcement, US Defense Department sources in Washington reported that the US military had completed its own planning for a variety of US operations against Syria, or for assisting neighboring countries in the event action was ordered – a reference, according to our sources, to Turkey, Jordan and Israel.
The Syrian civil war is now moving into a new phase of major power military intervention, say Debkafile’s military sources.

Moscow, by sending troops to Syria without UN Security Council approval, has set up a precedent for the United States, the European Union and Arab governments to follow. They all held back from sending troops to Syria because all motions to apply force for halting the bloodshed in Syria was blocked in the UN body.

According to US military sources, in recent weeks, the Pentagon has finalized its assessment of what types of units would be needed and how many troops. The military planning includes a scenario for a no-fly zone as well as protecting chemical and biological sites.

Alarming if true.

However, on 12 June DEBKAfile had the following announcement: “Syria is being further wrenched apart as a result of US President Barack Obama’s maneuverings for winning Russian cooperation in resolving the Syrian conflict for US concessions in the nuclear controversy with Iran: Russia is cementing its grip on Syria’s Mediterranean coast while pushing its civil war-torn heartland over to the Americans.
To spoil the Russian game, the US hopes to draw Damascus into the Syrian revolt, a goal only achievable with air force aid.”

Agreed upon Action?

I think the real danger lies in Assad makes good his cousin Makhlouf´s threat to attack Israel