Mike Callaghan is Director of the Lowy Institute's G20 Studies Centre.

We thought it was settled. With the election on 7 September, Bob Carr was going to represent Australia at the G20 leaders' summit in St Petersburg on 5-6 September. I suspect Prime Minister Rudd wanted a later election so that he could have gone, but ALP strategists were concerned about the electoral honeymoon fading.

Now the rumours are running that, given the situation in Syria, Rudd may make a dash to St Petersburg before zipping back for the election. Dennis Atkins in the Courier Mail thinks the G20 summit could give Kevin Rudd a boost.

But it is hard to believe that such a visit is seriously being contemplated. Certainly if Bob Carr goes, he has an unenviable assignment. A foreign minister is obviously out-ranked at a leaders' summit. Bob Carr will struggle to get any bilateral meetings. Moreover, there will be the question over his head as to whether he will still be foreign minister the day after the summit (of course the same uncertainty would surround Kevin Rudd).

The main action in St Petersburg is likely to take place in the margins of the meeting and not at the G20 summit itself.

Expectations of big outcomes on the economic agenda are low. Domenico Lombardi from the Center for International Governance Innovation said 'The forthcoming G20 summit in Russia may, unlike previous summits, be an event with no immediate, significant deliverables'. It is a bleak assessment, particularly when it is so hard to point to many 'immediate, significant deliverables' from the last few summits.

There are not likely to be any major negotiations on the economic front in St Petersburg, so Rudd will not be missing much on this score. But this is a problem for the G20. Its inherent strength is the involvement of leaders and the opportunity for them to tackle some intractable global economic issues. Hopefully the situation will be different at the Brisbane G20 summit in 2014.

President Putin's comments in the lead-up to the summit suggest some ambitious outcomes: 'we are to finalise decisions for promoting capital markets development, establishing more efficient financial regulation and infrastructure both globally and nationally, strengthening the multilateral trading system, enhancing energy and commodity markets sustainability, and fighting corruption'.

On all scores, it is more a case of work in progress, although Russia has done a commendable job pushing things forward. However, Russia has not focused on seeing whether leaders could make a big breakthrough on a priority area. The main take away from the St Petersburg summit may be the endorsement of the OECD's action plan on combating corporate tax avoidance.

And the outcome from St Petersburg is unlikely to placate the many critics of the G20. As Pierre Siklos observes, the G20's united front has dissipated since the heady days of the 2009 London summit. But as the Russian chair has rightly emphasised, the global economic outlook remains anything but encouraging. The focus of the emerging markets will be on the impact of an exit from quantitative easing by the US Fed. China has said this will be its focus at the summit. And there are some dire warnings that badly handled exit strategies could be the source of another crisis.

The US Fed's exit strategy will not get a mention in the communiqué, but it is to be hoped that Syria and other events do not divert leaders' discussions away from this important topic.

A military strike on the eve or while the summit is being held could create tension. After cancelling his meeting with Putin in Moscow, it was only last Monday that the White House confirmed presidents Obama and Putin would meet 'in some way' in St Petersburg. The same cannot be said of China's president Xi Jinping and Japan's prime minister Shinzo Abe, who will not be meeting in St Petersburg.

The St Petersburg summit could be a messy  affair. Should Kevin Rudd go? As I have said before, Australia should be represented at the leaders' summit because the G20 is important. Attendance should not be based on electoral considerations.

Photo courtesy of the Defence Department.