The UK Government’s stated legal justification for targeted strikes against a Syrian chemical weapons factory is that they were necessary and proportionate acts of humanitarian intervention. Most legal experts, however, have argued that, applying every conceivable type of interpretive gymnastics, the strikes were ‘simply, unconditionally, unambiguously illegal’ since they did not fall within any of the exceptions to the general prohibition on the threat or use of force under article 2(4) UN Charter. On this issue, there appears to be little difference among legal expert opinion.
However, the effect of the recent strikes on domestic constitutional controls on the use of force also warrants exploration.
Consulting Parliament: the constitutional convention
I have explained in a previous post the UK constitutional position on military deployments, but its worth a brief restatement here. Prior to 2003, Parliament was never consulted in advance on military deployments – and when it was wconsulted, it was largely a symbolic vote after the fact.
Such an event is particularly serious in light of the weakness of the other constitutional controls
However, in 2003, pressure from Parliamentarians and the public forced Tony Blair to seek Commons approval in a non-binding vote on whether to invade Iraq. This constitutional convention to seek Commons approval was applied in the NATO-led bombing of Libya in 2011 (though military action had already begun before Parliament voted) and then in 2013 – echoing events of the last week – when David Cameron asked for Commons approval to bomb Syrian government targets after the alleged use of chemical weapons. He was voted down, and although constitutionally he was under no obligation to follow the vote, he honoured the will of the Commons and refrained from the strikes – though a future vote did authorise military strikes in Syria to target ISIS.
Theresa May’s refusal to consult Parliament
Prime Minister Theresa May’s refusal to consult Parliament in advance of the recent air strikes in Syria has substantially undermined the emerging constitutional convention outlined above. While caveats to the convention do include ‘critical national interests’, there is always the danger, particularly with a prerogative power which presupposes ‘executive innocence’, that the exception can consume the rule.
Further, refusal to honour the convention to seek Commons approval cannot be challenged in the UK Courts. There is ample judicial cognisance of the unenforceability of Constitutional conventions, most recently in the Miller litigation, where although the Sewel Convention was statutorily recognised by the Scotland Act 2016, it was deemed to have no legal effect.
Neither are deployment decisions, more generally, challengeable in the UK Courts. In the absence of an objective standard to scrutinise deployment decisions (which could emerge with a ‘War Powers Act’), deployment decisions are considered a matter of high policy and thus a forbidden area of common law review. The reasons for the non-justiciability of military deployments have usually pertained to the apparent institutional incompetence of the courts to review what they describe as political decisions; deference to the executive on national security issues; and a judicial hesitancy to deal with ‘polycentric adjudication’.
deployment decisions are considered a matter of high policy
Despite multiple efforts to statutorise the role of Parliament in military deployments – which may have the incidental, though important, effect of making deployment decisions reviewable in the High Court – Theresa May’s military action has severely undermined the already delicate role that Parliament plays in scrutinising deployment decisions. Such an event is particularly serious in light of the weakness of the other constitutional controls on the prerogative power, particularly in the shadow of the Chilcot Inquiry, which highlighted the litany of institutional failures in the lead up to and execution of the Iraq war. Further, as no published evidence of Syrian Government responsibility has yet been provided, such strike action the presumption of innocence, displays an inattentiveness to the impotence of earlier US airstrikes on the Sharyat airbase, and a wilful ignorance of the state to which military intervention reduced Iraq.
 CND v. Prime Minister of the United Kingdom  EWHC 2777
 See Tanzil Chowdhury, ‘Taming the UK’s War Prerogative: The Rationale for Reform’ (forthcoming) (2018) Legal Studies
  UKHL 16
Photo: Hannah Bouattia