Syrian Crisis: Red Lines and Green Lights.

Regionwide war could break out if , in response to US and UK cruise missile strikes, Iran steps up the arms supply to Assad's government and its proxy Hizbollah attacked Israel. Then Israel, a nuclear power, may well decide to try and use the rhetoric about WMDs to take out Iran's suspected WMD sites.

Israel has kept fairly quiet during the Syrian crisis and threats of military action against Syria. Some Iranian spokesmen and commanders have made oblique statements about how an attack on Syria would 'fan the flames' of 'outrage' across the Middle East.

If Israel sees Assad or Hizbollah as being directly supported by Tehran while they are attacking Israel it could deliver an ultimatum to Iran or just act if the situation on the ground deteriorates into an ever greater life and death struggle between Assad's most Shia Alawi backed government and majority Sunni militias.

Another regional flashpoint is Bahrain. The tiny Gulf Kingdom is ruled by a Sunni monarch in a land where 70% of the population is Shia. Since the Arab Spring of 2011 there have been revolts and riots so bad that Saudi forces had to roll in and crush the protests.

If Qatar and Saudi Arabia step up their arms supplies to the insurgent groups they are backing in Syria further ( they did on August 25 after Western military intervention was first put forth ) Iran could, if pushed too far, try to stoke up unrest to increase its regional influence against Saudi Arabia.

Bahrain was relatively stable in 2013. However, in July Shia terrorist groups were already setting off explosions in order to exacerbate sectarian tensions. Bahrain is also the naval base for the US Fifth Fleet which would be used in Tomahawk cruise missile strikes against Assad's Shia state.

Tensions are simmering in Bahrain because leading members of high society close Bahraini royal court such as the Salafist Sheikh Faisal al-Ghurair las month announced “We are happy to tell you that we have sent arms and ammunition to the mujahedeen in Syria”.

However, the real tensions that could create the greatest instability would be the chaos in Syria developed greater and turned into a failed state such as Afghanistan, not least as Saudi Arabia is terrified not only by potential Shia opposition in the east near main oil producing zones but Al Qaida 'blowback'.