A clear mandate and robust rules of engagement, as in the case of East Timor, are perceived as significantly contributing to the success of any intervention. Therefore, Australia also secured a clear mandate and robust rules of engagement before intervening in the Solomon Islands. This was the reason Canberra wanted a resolution passed by the local parliament.
The third step to be followed in future multilateral interventions will be to devise an exit strategy. In 1999, in order to intervene in East Timor, Australia demanded that the multinational force should be replaced as soon as possible by a UN peacekeeping operation. For several reasons, Canberra did not wish to be trapped in a long-term commitment in Timor. Medium-to-long-term commitments by the Australian Defense Forces (ADF) are not only costly, they also threaten to overstretch the troops. For these reasons, Howard did not wish to be trapped in a long-term police and military commitment in the Solomons. Thus, as soon as law and order were restored, Australia started to scale down its police and military presence.
In sum, Australia may well play the role of the regional sheriff again in the future. But under current policy, Australian-led multilateral interventions will likely occur only when explicit authorization, a clear and robust mandate, and an exit strategy are all guaranteed.
The sheriff policy and the Howard doctrine are actually different things. the sheriff policy is thoughtful, multilateral and consistent with international law. The Howard doctrine of unilateral preemptive strikes is none of those.
The Howard doctrine, of course, is not intended to be implemented, ever. Proclaiming it loudly has major domestic advantages, but actually following it would not. The 3 tests the Howard government uses for its intervention strategy were not applied in Iraq, and that's a great pity.
Even the exclusion of the UN from the intervention policy is likely a temporary feature that will fade with time.