In this context, which was eventually modified, and always subject to criticism, when it became clear toward the end of 2003 that Iraq did not possess WMD, by the 2004 updating of rhetoric to “Iraq had only had the potential to acquire and use them”, and the official line that terrorism was a result of regime change in Iraq (which escalated the activities of guerrillas and insurgents). Just as the Afghanistan and Iraq wars have called for an acceptance of law and legitimacy, they have also raised questions regarding the suitability of such terms as “insurgents, guerrillas, rebels, resistance members, terrorists, detainees, prisoners of war, lawful combatants, unlawful combatants, military commissions, competent tribunals, as well as others expressions.” What is required at present is a critical need to clarify concepts of law and legitimacy in the wake of these invasions.
Kofi Annan, the then Secretary-General of the United Nations had displayed tact and skilful diplomacy in all his interactions with the United States government. It is an indication of the gravity of the violation that he openly questioned the legality of the Iraq war. Other notable diplomats too joined Annan in his condemnation of the war. For example, A.M. Slaughter argued that the invasion of Iraq by America and its allies “was categorically illegal under international law”. Richard Falk noted that “the illegality of recourse to war against Iraq in 2003 was clear. It was also clear before and after the war that there was no reasonable basis for invoking the ‘illegal but legitimate’ formula used by the Independent International Commission for Kosovo to deal with an exceptional circumstance of humanitarian emergency.” The academia across the world was also of a similar view. A majority of influential diplomats and political commentators outside of the United States concurred with these views.
The sentiments of people outside of the United States in this debate are understandable. For example, there are widespread concerns regarding American hegemony in general and its foreign policies in particular. The adoption of a philosophy of unilateral action made the concerns all the more real. American policies tended to focus heavily on its security. The rationale was that if the only superpower in the world were to be secure, world security as such will advance. This sounds reasonable at a theoretical level. But the actual results tell a different story. For example,
“Although from the perspective of some countries such world security would correspond to and be subject only to American interests and values and, from their point of view, necessarily adverse to theirs. Concerns over such an outcome have been levelled at many of the key foreign policies of the George W. Bush administration.” 
The meaning of Article 51 of the UN Charter is of relevance in determining the legality of the war in Iraq. Most legal professionals and civil law experts agree that the words “armed attack” mentioned in Article 51 of the 1945 edition must be read literally. In other words, there must have been material damages suffered by the affected nation before there can be a legitimate military response against the instigator. But there is a problem with such an interpretation. The weaponry and military systems of now are far more advanced than the ones used in 1945. With the acquisition of nuclear technology, a country can annihilate its target with the push of a button. All it takes is a few seconds and there is virtually no time to defend or respond. The judiciary is now gaining an understanding of this new reality and hence has come to accept “pre-emptive or anticipatory military action” as a lawful one. Without such proactive actions international peace and security will be jeopardized. So, if the U.N. Charter were to be read literally, the Iraq war is illegitimate. But, when it is placed in the context of advances in military technology and interpreted more broadly, the Iraq war may be declared a lawful one.