This was never feasible. U.S. policy makers should have known this from the onset. France and Germany repeatedly and in fairly great detail (post-invasion risks, gap between what is required to declare war and what evidence existed, etc., many of which proved prescient afterward when insurgency developed and no new WMD were found) outlined why they opposed a war. They were famously dismissed as "old Europe." China's and Russia's interests were not aligned with actual or perceived U.S. interests in Iraq, meaning that there was no chance that they would aid the war effort in any meaningful fashion. Russia correctly saw regime change in Iraq as posing a threat of regional instability and the overall balance of power that maintained reasonable stability, both with possible risks for its "near abroad." China favored non-intervention, as its focus is on sustaining its economic growth and evolution to great power. Intervention, it felt, would risk inviting pressure, even creating de facto license for intervention, in its own terrorities in which disputes exist or on behalf of movements aimed at fundamental political change. It also knows that its hunger for resources depends on having working relationships with a wide number of countries to minimize disruptions, even if those countries have harsh regimes.
