Airports: Why join the dog-fight over Heathrow?
There's a big prize being sought by both Edinburgh and Glasgow airports, and it's not just better links with London.
They've got used to the logistical and political bottleneck around London airport expansion. So their eyes are on the prize of a direct link with China.
That became a much closer prospect on Tuesday, with an agreement between the Westminster and Beijing governments to liberalise direct air links.
No longer will there be a limit of six airport destinations in each country. The number of flights could double under the new agreement.
China would be a symbolic breakthrough for Scottish airports competing for new routes in the evolving air travel market. It shows that wide-bodied planes, such as the Boeing 777, can economically replace the 'Hub and Spoke' model of mega-airports by scheduling direct flights.
The ambition of leaping across continents has already been realised with a weekly chartered link between Scotland and Korea.
You can now fly directly from Edinburgh or Glasgow to Istanbul, Abu Dhabi, Dubai and several North American airports.
On Tuesday, Edinburgh Airport announced September international passenger figures up 21% on the same month in 2015. Unusually, that's while domestic traffic fell 2%.
It is crediting new routes started since last year to Helsinki with Finn Air, with Vueling to Rome, Paris and Alicante, on 11 mainly sun-bound routes with Jet2, Wow Air to Reyjkavik, easyjet to Stuttgart, Vienna and Venice, and Ryanair to Copenhagen.
In Glasgow, the September figures saw 4% growth, slowing a bit with equal levels of growth for domestic and international. It reported 12% growth on travel to and from EU destinations, including Paris, Brussels, Milan, Barcelona and a new link with Sofia in Bulgaria.
Indeed, growth is now so strong for these airports that those of an environmental frame of mind might wonder whether it is really necessary to cut Air Passenger Duty in half, as the Scottish government aims to do.
However, under the same ownership as Glasgow, Aberdeen Airport completed the monthly passenger picture, and with a now-familiar tale of decline. The oil and gas sector's woes have taken passenger numbers down 15% on September last year, with domestic and helicopter traffic falling faster than international.
Management at Dyce is pinning its hopes on more leisure travel, with links to Latvia and Ryanair returning from February, with tourist routes to sunnier prospects.
If the increased links, particularly the long-haul ones from Edinburgh and Glasgow, can reduce the short-haul flights to feed the big planes in big airports, then that could have a (relatively) positive environmental impact. They may, crucially, appeal more to inbound travellers, who don't want the hassle and delay of hubs.
And that may be the longer game for Scottish transport links than getting involved in the dog-fights around the crowded political skies over Heathrow and Gatwick.
The failure to choose how and where to expand London's airports can be viewed as another symbol, this time of Britain's failure to plan long-term and take difficult decisions.
The Scottish government has long taken the position that it doesn't care which airport expands, so long as one of them does. Ministers have been heavily lobbied to back Heathrow or Gatwick, but have avoided taking sides.
So at first sight, the announcement this week that they're backing Heathrow seems an odd one. If they want to influence the outcome, why wait years, until a week or so before a decision is made by UK ministers?
The answer from economy minister Keith Brown is that they have a deal with Heathrow which would help the Scottish economy. Understanding this deal requires a bit of context.
There's little in it that Heathrow had not offered long ago. It not only has to promise links with Scottish airports, once capacity has been increased. The whole 'hub and spoke' airport business model requires that to happen. As it is, Heathrow is at risk of becoming all hub and not much spoke.
The claims of adding 16,000 jobs - as I've noted when Heathrow came a-wooing last year - is based on a very long-range economic forecast, which suggests Scotland might get there by 2050.
And the idea of Prestwick could become a logistical centre for building a runway 400 miles away? Well, let's politely note that there's to be an "investigation into the potential" of that. If it stacks up to anything, it's hardly likely to be the elusive game-changer for the Scottish government's loss-making Ayrshire airfield.
This memorandum of understanding was with the managers of Heathrow. What is less clear is the detail of the understanding with the UK government, but we could assume that there is one. The publicly stated deal doesn't look worth the level of political commitment.
As Keith Brown indicated on the BBC's 'Scotland 2016', he expects that the government funding for airport expansion is going to see a share of capital spending allocated to Holyrood under the Barnett Formula. As a national asset with those spin-off effects on the whole UK economy, that wasn't guaranteed.
Fractured and unpredictable
And whatever else is in the mix, the pledge of SNP support for Heathrow's expansion looks like it's been choreographed to precede the Downing Street decision.
Theresa May can now face down her own Westminster colleagues, including the Heathrow-sceptic Foreign Secretary Boris Johnson. She can tell them that lots of them can rebel over Heathrow's expansion, but the prime minister now has 56 SNP votes going through the Heathrow lobby with her.
With the politics of Westminster increasingly fractured and unpredictable, this may be a sign of things to come, with policy decided by new and shifting alliances. The same sort of deal could be done on high-speed rail, if MPs from the Tory shires threaten to block it.
And if the Tory party can't agree on how to go about Brexit? Well, the SNP group is sitting there with those 56 votes, should the prime minister choose to change tack and take the softer, more Europhile route.