It is uncontroversial that the invasion and occupation of Iraq involved the following errors: the misinterpretation of intelligence; the underestimation of the number of troops requisite for law and order; the disbanding of the Iraqi army; and indiscriminate debaathification of the civil service. The first error was one of imagination rather than virtue; the others were caused by ‘callousness”, impatience, and consequent imprudence. These vices were partly responsible for massive civilian casualties, which many wrongly assume to teach the fundamentally erroneous character of the invasion. Nonetheless, we should beware such moral flaws in tomorrow’s policy-makers and renounce the managerial mentality that fosters them.
Another lesson is that, in so far as nation-rebuilding requires substantial and long-term commitments, it must command the support of the nation-builder’s domestic electorate; and to do that, it must be able to justify itself in terms of the national interest. From this we should not infer the further lesson that morality’s reach into foreign policy is limited, since, according to Thomist ethics, the pursuit of the national interest can itself be moral.
Finally, one lesson that we should not learn from Iraq is never again to violate the letter of international law and intervene militarily in a sovereign state without Security Council authorization. The law’s authority can be undermined as much by the UN’s failure to enforce it, as by states taking it into their own hands. It is seriously problematic that the current international legal system denies the right of individual states to use military force unilaterally except in self-defence, while reserving the enforcement of international law to a body, whose capacity to act is hamstrung by the right of veto. Given this situation, military intervention without Security Council authorization could be morally justified on certain conditions.