Kazakh president Nursultan Nazarbayev, Russia's President Vladimir Putin and Belarus President Alexander Lukashenko speak during their meeting in Putin's Novo-Ogaryovo residence outside Moscow, on March 5, 2014. - 

Tomorrow – assuming that peace doesn’t break out overnight – EU leaders will meet to decide how best to punish the Russians for their incursion into Crimea. Full blown economic sanctions seem unlikely. Russia is an important trading partner for Europeans. The Brits want the roubles to keep on pouring into their financial center. The French aim to sell the Kremlin a few warships. And Germany depends on Russia for about a third of its natural gas.

But “smart “ or “individual” sanctions are a possibility.

"We should put together a package of asset freezes, targeting specific companies controlled by Putin and his oligarch friends," says British Conservative lawmaker Brook Newmark. He argues that nothing is more likely to enrage members of the Russian elite than a curb on their ability to enjoy the money they have stashed abroad.

Anne Applebaum, Pultizer Prize winning author and expert on Eastern Europe, agrees that smart sanctions are an option. Certain members of the Russian elite are vulnerable.

"They own homes in London and the South of France," says Applebaum. "Their children go to school in London. So yes, they’re very dependent on their ties especially to London, but also to other European capitals."

But -- she claims -- Putin might be difficult to target because his money is well-hidden.

Few people know more about the mechanics of smart sanctions against Russians than Bill Browder, Chief Executive Officer of Hermitage Capital Management. Once the biggest foreign investor in Russia, Browder fell foul of the Kremlin after exposing corruption. His lawyer, Sergei Magnitsky, was later detained, and died in custody in murky circumstances. Browder lobbied for The Magnitsky Act, which has so far imposed asset freezes and visa bans on more than a dozen Russian officials. Browder argues that Putin could certainly be targeted too.

"He has lots of assets in the U.K., France, Germany and various places. I am sure there are plenty of intelligence agencies that have plenty of information about what Putin owns and where," Browder says.

Putin’s true net worth has not been published. Some estimates suggest it could be as much $70 billion.

And here’s the problem: The Russian leader and his oligarchs own so much wealth that freezing it all would be a monumental task. Take Chelsea Football Club, now owned by one of Putin’s closest associates, Roman Abramovic. Are the British authorities really going to seize it? It just goes to show – admits Anne Applebaum – how dependent London has become on Russian cash.

"There are many different types of people in London like real estate brokers and art dealers that effectively live off Russian money. And the U.K.’s  ability to restrict or control Russian money is limited by these kinds of links," she says.

And that - says Alexander Nekrassov, a former adviser to the Kremlin now living in London – is why Putin will laugh off any proposed smart sanctions from the U.K.

"Britain will never, never – in the world – target Russian oligarchs who provide billions and billions to the U.K. economy," he says. "So it’s very hard to see how it can influence Russia’s policy in Ukraine."

Nevertheless, Bill Browder maintains that smart sanctions can work and must be deployed: "We’ve had an unprovoked military invasion of a foreign country. There clearly has to be something done," says Browder. "Are we so poor that we’re going to entirely discard our principles?"