America's commitment to security, dignity and prosperity in Asia, facing up to global challenges, and some strong words on climate change – President Obama's just-concluded speech in Brisbane was a hybrid package.

I imagine other contributors will add context to his applause-evoking remarks on setting targets to reduce climate change, and they may well be perceived as a fairly blunt intervention into Australian politics. I'll confine my observations to the topic that had been touted in advance as the main theme of the speech: Asian geopolitics and America's rebalance to the region.

The speech was given at the University of Queensland, my alma mater, and I recall all too well that November is end-of-year exam time there. So it's only right to attempt a grading. On Asia, this speech scores a credit – solid and respectable, but not spectacular.

It won't go down in history as the speech that categorically revitalized the rebalance. But at least it held the line. It consolidated most of the messages that will likely keep the pivot alive for the next administration, and that's a start.

The speech emphasised the value of allies, Australia especially, and underscored an 'ironclad' American guarantee to their sovereignty and security. It stressed the need to resist an outdated international politics based on spheres of influence, bullying and coercion, and instead reasserted American support for peaceful management of disputes based on norms and the rule of law – like a Code of Conduct on the contested South China Sea.

It reinforced US support for effective Asian regional institutions like the East Asia Summit and acknowledged recent progress in dialogue and military communications between the US and China, to help ensure incidents at sea do not escalate to conflict.

And Obama reminded us of the progress being made in maintaining and modernising alliances and partnerships, such as the Marines rotation to Darwin, new defence guidelines with Japan, missile defence with South Korea, wide-ranging alliance renewal with the Philippines and help with improved maritime patrol capabilities in Vietnam. He welcomed India's emergence as a power and partner in the Asia-Pacific and encouraged US partners and allies to cooperate more among themselves. He noted plans for the US to ensure that by 2020, more than half of its air and naval power will be in the Pacific.

For allies and partners, that is all well and good, even if it's nothing they haven't heard before.

Where Obama could have done better is in trying to reconcile his promised effort on Asia – 'the Asia-Pacific will always be a focus of our foreign policy' – with the reality of continued or even deepened US security attention this year to strife in Europe and the Middle East. Rather unconvincingly, he suggested that the involvement of the US and its Asia-Pacific allies like Australia in those situations somehow reinforced – rather than detracted from – the US rebalance to Asia.

The one way I can see a certain truth to this point is to say that American credibility anywhere is good for American credibility everywhere. And in Asia, despite all the handwringing about China's military modernisation (or Russia's peculiar new adventures), America's military edge is still such that the real question is not about the balance of power but the balance of uncertainty and resolve.

Which brings us to China. Sensibly, Obama's speech today did not directly challenge the legitimacy of the Chinese political system, in the way that his strong words in Canberra did just three years ago ('prosperity without freedom is just another kind of poverty'). 

Still, he did not resile from upholding values of democracy, freedom and human rights – linking them with themes of opportunity, innovation and youth - and pointedly included a reference to Hong Kong alongside Asia's democracies.

In these times when a rules-based liberal global order is under challenge from forces variously of destabilization, disorder, authoritarianism and sheer barbarism, Obama's Brisbane speech may not prove historic, but it has at least held the line. With clarity and conviction about the staying power of democracies, British Prime Minister David Cameron did at least as much in addressing the Australian Parliament yesterday.

With major public addresses in the days ahead by German Chancellor Merkel, Indian Prime Minister Modi and Chinese President Xi Jinping, it is an open question how much more history is to be made in this week that Australia was all the world's stage.