The UN Charter does not justify an invasion
Both the US and UK governments have succeeded in diverting attention away from the key issue that we should be debating at this point: the legality of the war. The war against Iraq is in contravention of the United Nations Charter and international law.
There are only two exceptional circumstances in which America or Britain could legally declare a war against Iraq: 1) If they were acting in self-defence. Article 51 of the charter preserves the right to self-defence where a state has been attacked. 2) If a UN Security Council resolution explicitly authorised force under Article 42 of the UN Charter, the Security Council having concluded that such force is necessary in order to secure international peace and security.
At present, there is no existing UN resolution that authorises the use of force and there is no threat to justify it.
The UN Charter provides the framework for the use of force in international law. Almost all states are parties to the charter, including Iraq, Britain and the United States. Article 1 of the charter sets out the United Nations' aims, the first of which is: "To maintain international peace and security; and to that end: to take effective collective measures for the prevention and removal of threats to the peace, and for the suppression of acts of aggression or other breaches of the peace, and to bring about by peaceful means, and in conformity with the principles of justice and international law, adjustment or settlement of international disputes or situations which might lead to a breach of the peace."
Article 2 of the UN Charter states that "all members shall settle their international disputes with peaceful means in such a manner that international peace and security and justice are not endangered. All members shall refrain in their international relations from the threat or use of force against the territorial integrity or political independence of any state."
No one can deny that Saddam Hussein has an appalling human rights record; yet that is no legal justification to over-throw his government. Colin Powell has stated that "past material breaches, current material breaches and new material breaches" provide the authority for the US to act, even without a new Security Council resolution. Yet there is no authority anywhere in the charter for a member state to decide to use force in order to enforce breaches of the Security Council resolution. On the contrary, that power is reserved for the Security Council (as stated in Article 42). It is only with an express delegation of that power that a member state may use force against another to make it comply with a Security Council resolution.
The burden of proof is on the American and British governments to prove the existence of a pressing and direct threat. They will also need to show that there is no effective alternative to the use of force. The minimum we can expect from these two self-appointed leaders of the civilised world is to seek to uphold the principles of the UN Charter to maintain international peace and security.