If you wonder what the attitude of our leaders - indeed all world leaders - to the crisis in Ukraine is, you are not alone.

The impression I have is that they don't know either.

But in the end, this comes down to two questions:

1) Is Russia going to back out of Crimea?

2) Are we going to try and make them?

Let's take question two first. Of course, our options are relatively limited.

We can rule out any kind of military strike straight away, which leaves us with diplomatic and economic options.

As much as Putin might not want to be chucked out of the G8, I rather doubt this is going to keep him awake at night. On the economic front, it seems clear from the statistics that we have more to lose than to gain.

Ukrainian servicemen carry flags as they leave Belbek airport in the Crimea region. Credit: Reuters

Robert Peston has just written a good blog, pointing out that in 2011 (the last year for which figures are available) we had investments in Russia of £46 billion, compared to Russian investments here of £27 billion.

In addition, Russia provides about a third of the gas consumed by Europe and European banks have a larger than one might like exposure to the Russian private and public sectors in terms of loans and debt.

Russian president Vladimir Putin has said he will only use force as a 'last resort'. Credit: Reuters

But America is less dependent on Russian resources and Russia is a less important export market for all of us than China.

Action is therefore possible if we were to decide the occupation of Crimea was an act that could not be allowed to stand.

The Russian economy is not that diverse or strong and there are plenty of diplomats who know the country well who claim there is more opposition to Putin than we might think.

US Secretary of State John Kerry has condemned Russia's 'act of aggression' in Ukraine. Credit: Reuters

Over time, economic sanctions might therefore work - if not whilst Putin is in power, then perhaps after he has gone (whenever that may be).

Taking action would have the benefit of warning him off further action elsewhere and sending a message to the likes of the Chinese to think carefully before throwing their weight around (our government is more worried than you might imagine about Chinese intentions in relation to Japan).

Russian president Vladimir Putin has delivered a robust defence of Russia's actions in Crimea. Credit: Reuters

But all that is to suppose that there is a degree of conventional Western real politik about the mindset of the current Russian leadership. And, as this perceptive blog in the New York Times today argues, that might be a mistake.

Western leaders therefore have to consider the possibility that:

1) We decide to make Russia back out of the Crimea.

2) The Russians take absolutely no notice.

This would potentially lock us into a very long, very costly - and possibly very pointless - exercise, which could go on for years and years.

You can see why they are, so far, not speaking with much of a sense of purpose.

Watch: New footage of tense stand-off between Russian and Ukrainian troops in Crimea