"We declare the freezing of the Mehdi Army without exception in order to rehabilitate it in a way that will safeguard its ideological image within a maximum period of six months starting from the day this statement is issued,"Yes this could be a window for a British withdrawal, but frankly people who "hail" this kind of act are, frankly, imbeciles. Any action is purely for Sadr's own personal advantage, be it organizational or in terms of re-supply and training. After 6 months the militia will be harder an stronger.
British Troops should use the opportunity to re-assert authority in Basra, THEN pull out. If the Sadrist forces cannot resist engaging, then their cover is blown and would have only done the same as a withdrawal commenced anyway - better to know this in a proactive operation than in a withdrawal, if you ask me.
I have for many years mistrusted this slippery operator. He knows when to melt away at a convenient time. He is no fool. He is only out for his own interests (or is being manipulated by master-craftsmen). He is VERY dangerous. Alas, people seem addicted to appeasing, excusing and giving the benefit of the doubt to al-Sadr.