Pita Sharples cut a fine figure at the UN. But what, if anything, did it all mean?

Pita Sharples rather clandestine dash to New York to tell the UN that we now think its Declaration on the Rights of Indigenous Peoples is a grand idea is an object lesson in how to portray two half-full glasses as overflowing.

(Quick note to sub-editors around the country - New Zealand hasn't now "signed" this Declaration, as it is not a Treaty. We've simply changed our formal position on the UN General Assembly's decision to adopt it from "opposed" to "support with conditions".)

To see these different political narratives first hand, compare the press releases of Pita Sharples and John Key on this change. The former is big on the importance of the step in restoring New Zealand's mana on the world stage, and decidedly light on practical detail. The latter also nods its head at the importance of being seen to support indigenous rights globally, before quickly moving on to point out that nothing of substance will change in New Zealand as a result.

The Maori Party's strategy here is obvious. Pita Sharples was able to stand before the gathered indigenous peoples of the globe (his announcement was to the UN Permanent Forum on Indigenous Issues) and show Maori voters back in Aotearoa that his party can deliver something Labour steadfastly refused them.

Added to the forthcoming repeal of the Foreshore and Seabed Act, it can be woven into a story of Maori Party MPs succeeding in Government where previous representatives failed miserably. That story might start to look a bit thin if examined too closely - the Government's preferred alternative legislation for the Foreshore and Seabed looks a lot like what is in place at present, and New Zealand's agreement to the Declaration comes heavily caveated. However, these political compromises are ones that can more easily be lived with purely because of who has made them and how they were reached.

For National, the fact the Declaration has absolutely no binding force in domestic or international law, plus the fact New Zealand's support for it explicitly states that we will not change any existing legal or constitutional arrangements in order to comply with it, makes supporting it a comparatively safe step to take.

Doing so banks some credit with a support party, who may be asked to swallow yet more policy rats at a later date. And it is another slap to Labour's face - always remember that helping the enemy of your enemy can be as good as hurting them directly.

True, Rodney Hide's hissy-fit in the House created some collateral political damage that National would have preferred to do without, and might have avoided had it not continued to display some sloppy inter-party management skills. But even here there is an upside in giving ACT the chance to remember and flaunt its principles in public rather than engage in ongoing internecine warfare, if only to help it to survive as a viable force through to 2011 and beyond.

I think this win-win scenario in domestic politics explains why New Zealand has given conditional support to the Declaration now, rather than back in 2007 when it actually got voted on by the UN.

Had the then Labour Government tried the current trick of voting "yes ... but", it would have faced a double whammy. National would have harried them for yet more "PC-gone-mad" policy, while the Maori Party would have condemned them utterly for refusing to take the Declaration seriously.

By contrast, Labour has no official statement on the move up on its website, while Nania Mahuta is reduced to pointing out that it is: "A whole heap of window dressing of empty promises and hollow gains – meanwhile Maori unemployment continues to rise…" Which may be entirely true, but entirely begs the question of whether or not Labour supports or opposes the action taken!

Just as the 4th Labour Government in the 1980s could get away with introducing economic reforms that would have sunk a National administration, so too the National-Maori Party combination can manage moves on Maori-Crown relations that Labour could not.

All that said, you can argue that so far the fruit from this political relationship has been low hanging and thus easily plucked. Both National and the Maori Party have a strong interest in getting the Foreshore and Seabed issue off the table - there's no gain for either side in continuing the fight over it. And giving general agreement to a non-binding statement of indigenous rights is an easy move, to put it mildly - as was National's agreement to let the tino rangitiratanga flag fly on Waitangi Day.

From here on in, things may get a bit tougher. There's the fact that the burden of much of National's policy on matters to do with the economy, benefits, tax and ACC will fall more heavily on Maori than non-Maori. Whanau Ora will have to work out pretty well to off-set this cost to the Maori Party's support base.

And even on the broad "Treaty" front, the issues will get trickier. The promised "constitutional review" agreed to between the National and Maori Parties will have to consider the vexed question of what status the Treaty should have in law, as well as the highly charged matter of whether to retain the Maori seats beyond 2011.

And as a potential taste of things to come, consider this report on what Tuhoe are seeking by way of settlement of past Crown wrongs against them. It goes without saying that giving total control over the Urewera National Park to Tuhoe, let along seeing "Government functions like schools, health and welfare handed over to Tuhoe, with other functions - even tax - devolved over time", will tax the limits of National's preparedness to devolve control to Iwi.

Not that I'm predicting that the whole edifice will come crashing down in the next 18 months. There is good political reason for the two parties to keep on working together. Nor do I even hope that it does so. I think it is to the good of the country for the politics of protest to morph into the politics of compromise.

But I just hope that the Maori Party finds it has stronger reasons for staying in support of National than the need to pay off Pita Sharples' mortgage.