British Prime Minister David Cameron recently lost a vote in the House of Commons that would have authorized British participation in a military strike on Syria:
British MPs have voted to reject possible military action against the Assad regime in Syria to deter the use of chemical weapons. A government motion was defeated by 285 to 272, a majority of 13 votes. Prime Minster David Cameron said it was clear Parliament does not want action and “the government will act accordingly”. It effectively rules out British involvement in any US-led strikes against the Assad regime.
Whatever one thinks of the result, Prime Minister David Cameron at least deserves credit for seeking parliamentary authorization rather than simply making a unilateral executive decision to attack. The British government seems to understand that it is a bad idea to enter a war without a broad political consensus behind the decision. His actions are in sharp contrast to the Obama administration’s unwillingness to seek congressional authorization for its war in Libya or for a possible US military intervention in Syria. This, despite the fact that the need for legislative authorization under Britain’s unwritten constitution is far less clear than it is under Article I of the US Constitution, which gives Congress the exclusive authority to declare war.
From a strictly pragmatic point of view, Britain’s unwillingness to take part in an attack increases the risks for the United States, should President Obama decide to go forward without the support of our closest and most militarily potent ally. The US surely has the firepower needed to launch a strike without the aid of British forces. But their absence increases the burden on the US military and diminishes the international political legitimacy of any US-led operation.
UPDATE: It is not entirely clear whether the British constitutional tradition requires parliamentary approval for the initiation of war. In practice, however, approval has usually been sought in modern times. For example, in 2011, Parliament voted in favor of the Libya intervention.
UPDATE #2: This 2005 Guardian article has a good discussion of the relevant British constitutional history. As it points out, up until World War II, Britain usually declared war without a parliamentary vote. But since that conflict, parliamentary votes generally were taken, including for the Korean War, the 1991 Gulf War (though only after the deployment of troops), and the Iraq War in 2003. Since then, MPs have also voted on the Libya intervention and – most recently – on Syria.