Regarding the ceasefire in 687, there is no clause in that resolution from which one could infer a “right” to restart hostilities if Iraq does not comply with the requirements laid out. To the contrary,
“34. [The Security Council] Decides to remain seized of the matter and to take such further steps as may be required for the implementation of the present resolution and to secure peace and security in the region.”
It is hard to read that any other way than to mean that the UN Security Council would have to decide whether “further steps” would be required for implementation.
Furthermore, as previously stated, the ceasefire is with the UN. Neither the US, nor Britain, nor France, nor any other member has the standing to un-do a UN resolution.
The point is well taken that 1441 notes that there are no-fly zones in effect. However, that resolution does not have any automaticity in authorizing the use of force by member states. This was acknowledged by Ambassador Negroponte at the time the resolution was passed.
1441 does note that Iraq “will face serious consequences” if it continues violations of that and previous resolutions.
Pulling back from the question of resolutions for a moment, the UN Charter holds that member states have an inherent right to self defense, and arguably anticipatory self defense, but only in those situations where the Security Council has not had time to consider the matter. That is clearly not the case here.
Even more generally, if one accepts the legal (as opposed to moral or practical) legitimacy of the United Nations, it is extremely difficult to see how there can be any other ultimate authority on the meaning and intent of actions by the UN, aside from UN bodies themselves. That a single country can seek to define the meaning, intent, and application of the UN Charter or UN resolutions would contradict the acknowledgement of legal legitimacy.