Sam Roggeveen is right to suggest that 'credibility' will be a major factor for President Obama in his decision to mount military strikes against Syria in response to the use of chemical weapons. Sam is also right to suggest that such action will not mean that crisis in the Middle East has trumped the rebalance to Indo-Pacific Asia as the long term priority in US strategic policy.

It is worth adding that these two points are intimately connected. If or when the Obama Administration launches those cruise missiles from warships in the Mediterranean, the accompanying diplomatic signal of resolve will be aimed as much at audiences in Asia as in the Middle East. Think in particular of Japan and South Korea, two US allies constantly watching for cracks in the credibility of their respective alliances with America, and the umbrella of 'extended deterrence' it provides against North Korea and (for the Japanese at least) China.

The need to reinforce international legal prohibitions and norms against chemical weapons use also has a strong Asian dimension. The Japanese, in particular, have long been concerned about North Korea's chemical weapons capabilities as well as its nuclear program.

All of this will only add to the pressure for Obama to use punitive force against Syria – and to the long-term negative repercussions for American credibility in upholding Asian stability and security if he does not.