What does Putin want from Ukraine and how might he go about achieving it?

Ukraine finds itself at the centre of crisis which has been eight years in the making. Now the decision on whether to invade rests with one man - Vladimir Putin. What does Putin want? Arguably all world leaders are fixated on the past as they navigate the future, but President Putin seems obsessed with recovering the prestige he feels Russia lost during the Soviet Union’s collapse. When the wall came down in 1989, the Soviet Union splintered with it. Putin’s grievances were seeded in the alleged promises made to Russia, that NATO would not expand east. In fact then-Russian president Boris Yeltsin gave the green light for Poland to join NATO a few years later and Russia signed a treaty guaranteeing Ukraine’s sovereignty in 1994, but Putin’s sense of betrayal still persists.

So what are the options for Putin? One might involve formally recognising the separatist territories around Donetsk and Luhansk. This week the Russian parliament called on Putin to do just that.

If he did, Russia might help the separatists fight Ukraine for the control of the remainder of those regions or oblasts currently controlled by Ukraine.

Overnight, the Donetsk People's Republic (DPR) accused Ukraine of shelling them, something the Ukrainians have denied.

But this is precisely the kind of pretext analysts have feared will be used for either sending Russian troops into the separatist areas or significantly increasing the military supplies to fighters there.

It might also be the precursor to Russia formally annexing the two regions, and incorporating them into the Russian Federation.

The Head of the DPR, Denis Pushilin, told me via video link last week he wouldn’t rule out Russian troops stepping in, if there was an escalation by the Ukrainians. Russia may decide to push north from Crimea, securing the North Crimea canal, a vital water source cut off by Ukraine eight years ago and establishing a Russian controlled corridor along the coast.

Russia put out video a couple of days ago, suggesting heavy weaponry was being moved out of Crimea, but satellite photos suggest there has in fact been no significant draw down.

In fact, the US says more troops have actually been added to the tens of thousands now surrounding Ukraine.

Finally, the most extreme option would be an assault on the capital Kyiv, combined with invasion from the east and south.

Regime change might sound attractive to President Putin, but he knows how that went in Iraq for the Americans. It could lead to a lengthy and bloody insurgency.

But despite the risks for the Russians, the latest satellite imagery from Maxar shows a new pontoon bridge over the Pripyat river in Belarus just four miles from the border with Ukraine.

Reports Thursday morning suggest the bridge may have been removed, but experts think it could be reinstated rapidly.

If this is all a bluff, it is getting extremely elaborate.

What are the possible solutions? One idea floated by President Macron during his recent visit to Moscow is so-called Finlandisation, making Ukraine neutral like Finland during the cold war, taking NATO membership off the table.

But there’s a major problem with that - joining NATO is literally in Ukraine's constitution and overturning that would be political suicide for any Ukrainian President.

The numbers in the Ukrainian parliament just don’t stack up to change Ukraine’s law to allow this to be possible.

As political analyst Tara Berezovets told me, joining NATO and moving closer to the EU is in Ukraine’s DNA.

'Any politician in Ukraine who would only try and make a political statement about dropping NATO membership is doomed,' Mr Berezovets said

It means we are at a stalemate, with Ukraine resisting neutrality to placate Russia, the west unwilling to commit troops to protect Ukraine, and Russia feeling threatened by Ukraine’s increasing embrace of liberal western democratic values.

The Minsk II agreement seems unworkable. Ukraine interprets it as a way of reasserting control over the breakaway regions, whereas Russia sees it as obliging the government in Kyiv to give the separatist areas more autonomy and effectively a veto over joining NATO or other aspects of Ukraine’s foreign policy.

With Ukraine and Russia at loggerheads about what Minsk actually means, implementing the agreement remains a conundrum. Now Russia and China have announced their joint opposition to NATO expansion, and with Russia supporting China’s claims over Taiwan, suddenly it seems President Putin’s ambitions may also be much greater than Ukraine - to seek a new world order, one in which the US is no longer dominant, and Russia and China are the pre-eminent alliance.