Berezovsky v Forbes: Libel Tourism, International Contracts and International Private Law

In 1996 the American magazine Forbes published an article written by Paul Klebnikov describing Russian businessman Boris Berezovsky as being connected to organised crime and corruption in Russia. Berezovsky argued that the article seriously damaged his reputation. Although the magazine was produced and primarily circulated in the United States, a limited number of copies were distributed in the United Kingdom. On that basis, Berezovsky brought a defamation claim before the High Court of Justice (England and Wales) against the publisher and the author.  Can the court hear the case and which law will apply to the case - the law of the US or the law of the UK? This question is very important because libel provisions are extremely different in the US and the UK tort law. And if the legal systems differ so much, how do we know what law applies to international contracts and liability?