Limiting the royal prerogatives

This is interesting: new UK Conservative party leader David Cameron has announced a an ambitious policy of constitutional change - centered around the limitation of the royal prerogative to wage war. At present, this power (along with the power to make treaties, appoint judges and other officials, and change the structure of government) is exercised on behalf of the Queen by the Prime Minister and Cabinet. But if Cameron has his way, these powers will be devolved to Parliament - leading to far greater democratic scrutiny of executive decisions.

I'm not sure about the desirability of all of these powers being devolved - while Parliamentary hearings on appointments is a good way of uncovering cronyism, it is also a quick step to US-style politicisation (and that goes double for judges). But I'd certainly agree with limiting the power of the executive to make treaties and wage war however and whenever they see fit. These are some of the most important decisions a government can make, and therefore deserve the very highest scrutiny. And while it won't solve the Iraq problem of a government hyping the threat to lie its way into a war, it will at least mean that the government's claims can be challenged, and provide for clear accountability afterwards.

As for New Zealand, we already have limited Parliamentary scrutiny of treaties (through the Foreign Affairs, Defence and Trade Select Committee), but the executive still has full warmaking power. Perhaps that's something someone could try and address through a private member's bill...?