Two months into anti-government protests in Syria last year, as the military crackdown grew more vicious, the European Union and US introduced sanctions against President Bashar al-Assad, his security chiefs and members of his family.

The sanctions were designed to freeze property and bank accounts, make it harder to access money and move assets around, and, ultimately, bring about an end to the violence. Eighteen months on, though, the fighting is worse and Brussels and Washington are struggling to make these sanctions bite.

There is no official tally of the amount of Assad riches frozen by the U.S., EU and Arab League under targeted sanctions on individuals and companies. But based on the amounts known to have been blocked by Britain and non-EU Switzerland, it is likely to be several hundred million dollars.

Switzerland has blocked about 100 million francs ($106 million) in assets linked to Assad, his associates and Syrian companies, in line with EU sanctions. Britain has frozen Syrian assets worth about 100 million pounds ($160 million), a source familiar with the situation said in July.

But Western diplomats and experts in asset tracing say the search has unearthed only glimpses of a suspected international financial network supporting Syria's ruler and his inner circle.

Western governments appear to be more focused on applying a set of broad based sanctions, such as those blocking Syria's central bank from US markets and imposing curbs on trade and services including a European Union ban on Syrian oil imports.

In part, this may be because the size of Assad's personal wealth - the assets he could realistically offload to generate funds - is probably no more than $1 billion, according to private sector experts in corporate investigations. This is much less than the multi-billion dollar hoard that his opponents alleged he owned when the conflict began in March 2011.

Iain Willis, Director of Research at UK-based business intelligence company Alaco Ltd, said that early in the uprising "enormous figures" of more than $120 billion were being floated as estimates of Assad's wealth, based on the fact that the Assads in effect controlled most of the levers of the economy.

"In reality, while they certainly had fingers in an awful lot of industries, it's nowhere near that, in terms of what's realisable, liquid, practical and moveable. I would say one percent of that is likely to be a realistic figure," he said.

Efforts to freeze whatever money he does have access to have been hindered by lawsuits lodged by some of those who appear on sanctions lists, Russian and Chinese opposition, lack of intelligence resources, and perhaps even a policy to calibrate the amount of pressure on Assad to give him a path to exile.

"There's been a sense that at the end of the day it's not a lot of money, that it doesn't have a significant impact on the decision-making calculus of the leadership," said Mark Dubowitz, executive director of the Foundation for Defense of Democracies think tank in Washington, though he said he did not know this was fact.

"The other operating theory is that - and this is potentially pretty cynical - if your goal is to get rid of Assad and there is an opportunity to get him to agree to step down, potentially you don't want to go after his assets because you want to be able to give him an escape route where he can end up in exile and enjoy the fruits of his despotic regime. 'Let's not squeeze him entirely'."

Another explanation may be psychological tactics, said Charles Crawford, a former British ambassador to Bosnia and Herzegovina, Serbia/Montenegro and Poland who helped implement sanctions intended to topple late Serb strongman Slobodan Milosevic. He said sanctions officials might want to list some regime hardliners but not others to stir up paranoia.

But a simple lack of manpower may also have hurt. A Western envoy in the UAE, where Assad and the family of Rami Makhlouf, Assad's cousin and main financial ally, are believed to have assets, said the probe into their private wealth was valuable but "we just don't have the resources. There is so much happening in the region right now that there are many other issues that take priority."

Nick Bortman, Gulf-based head of London corporate investigation firm GPW's Middle East practice, said Bashar's wealth had been meticulously invested overseas, over many years, and behind multiple layers of proxies and offshore companies and in countries where disclosure laws were weak or not enforced.

"Such groundwork dulls the blade of broad sanctions regimes," he said. "Freezing wealth requires identifying wealth, and that ultimately comes down to accessing advisors and consiglieri figures, something beyond the typical remit of financial and commercial watchdogs and other would-be enforcers."

Information from Gulf states has been meagre, some Western officials say. A senior Western diplomat said: "We have been discussing with Russia and the Gulf countries in terms of our concerns they may be using their banking systems. It's not clear the extent that the regime money may have gone there."

There has been some progress.

Take Makhlouf, accused by European Union foreign ministers in May 2011 of bankrolling Assad. The tycoon has been under US sanctions since 2008 for what Washington calls public corruption. Brussels brought in its own sanctions last year.

In July this year, evidence released by the US Senate's permanent sub-committee on investigations into anti-money laundering weaknesses at HSBC showed that Makhlouf and his father Mohammed were beneficiaries of a trust established in the Cayman Islands by the British bank.

On August 16, the EU listed a Luxembourg company, Drex Technologies Holding, saying Makhlouf was the beneficial owner. It said Makhlouf used the firm to facilitate and manage his international financial holdings, including a majority share in mobile phone operator Syriatel, which the EU has previously listed on the grounds that it provides financial support to the Syrian regime.

Drex Technologies could not be reached for comment. Paolo Poveda, a client relations analyst at Panama law firm Mossack Fonseca, described as a registered agent of Drex in the EU listing, said they had resigned that position in June 2012. On Aug 30, the Swiss sanctions department listed the Luxembourg company.

Makhlouf could not be reached for comment and questions sent through Syriatel were not answered. Makhlouf is believed to live in Syria still.

Swiss prosecutors last year froze roughly 3 million euros held in a Geneva bank by Makhlouf, on grounds of suspected money-laundering. The money was unfrozen when Makhlouf appealed, saying it predated sanctions imposed by the Swiss last May.

Mahlouf's lawsuit was one of 35 legal challenges against the Syria sanctions at the European Court of Justice, according to one EU official. The majority of those are still pending. Several European officials said the bar for evidence of wrong doing was being set much higher than in the early months of the uprising.

In another case, a Syrian businessman, Emad Ghreiwati, was taken off the sanctions list this year after he challenged his listing in a lawsuit at the European Court of Justice. The court ruled there was no need to make a formal finding in the case, as he had been taken off the list, for undisclosed reasons, after his lawsuit was launched, an official said.

Asked about the pace of the EU's efforts to target Assad's circle, a senior EU official said it was up to member states to propose "ideas for potential candidates" and legal challenges to the measures had resulted in a more cautious approach.

"Sometimes when mistakes are being made, evidence that is put on the table is not strong and solid enough, then there is always a possibility for legal recourse. And we are having a few of them in front of European courts and we have to be careful, to have solid ground," he said.

Perhaps the most interesting case study is Romania.

Romania's former communist dictator Nicolae Ceausescu and Assad's father Hafez al-Assad had a long and warm friendship.
Romania-based Syrian dissident Mohamad Rifai alleges close ties continue between the two countries, specifically the Syrian ambassador to Romania Walid Othman, who is Rami Makhlouf's father-in-law.

Rifai, a dentist who left Syria in the early 1980s to study in then-communist Romania, wants the EU and the United States to investigate companies linked to Othman as possible havens and conduits for funds belonging to Assad and his extended family, including Makhlouf.

Former Syrian Oil Minister Abdo Husameddin said Othman was "one of the people making (money transfer) dealings on behalf of the Assad family." But Othman's opponents have produced no evidence of any wrongdoing.

A Romanian investigative journalism website called Rise Project published documents in May 2012 that show the extent of Syrian commercial activity in Romania, including companies owned by Othman's sons, but no evidence of any connection to Assad himself, or to his assets.

An EU diplomat who spoke on condition of anonymity said Othman's name and that of his sons and his daughter, Razan, were on a list of potential sanctions targets presented by Syrian opposition activists to the EU in mid-September. But Razan's was the only name that drew interest.

On Oct. 15 the EU added her and 27 other names to a list of individuals targeted by EU asset freezes and travel bans, bringing the total number of people facing such sanctions to 181. Razan Othman is married to Makhlouf. The EU said she was "associated with the Syrian regime and benefiting from it".

A Western official, speaking on condition of anonymity when asked about Othman, said only that Romania was one of several countries being studied as a potential location of activity by Assad's private financial network.-Reuters