Former Italian Prime Minister Silvio Berlusconi has been found guilty of tax fraud and sentenced to four years in prison. Incredibly for a leader of a Group of Eight nation, this is not Mr. Berlusconi's first conviction — he has been found guilty in three other unrelated trials — nor might it be his last: The media magnate and power broker is on trial separately on charges of paying for sex with an underage prostitute. (He proclaims his innocence on all charges.) And once again, courtesy of the peculiarities of the Italian legal system, Mr. Berlusconi is unlikely to serve his sentence. Whether he will resume his political career is much less settled, but history shows it is never wise to count Mr. Berlusconi out.

In this case, Mr. Berlusconi was charged with orchestrating a scheme a decade ago in which he used offshore companies to purchase the rights to American movies and then resold them to Mediaset, his media conglomerate, at high prices, both to avoid paying Italian taxes and to use the profits for a secret slush fund. The gains totaled about ?250 million, or some $320 million. Mr. Berlusconi was convicted, sentenced to four years in prison — which was instantly cut to one year because of a law aimed at reducing prison overcrowding — and banned from politics for five years. (All sentences are suspended pending appeals.) The other defendants, including a longtime business partner, were acquitted.

The decision marked the former prime minister's fourth conviction — amid dozens of cases — in a lower court in Italy, although it is the first since he relinquished the prime minister's office a year ago. In previous cases, he has been found guilty of perjury, corruption and false accounting. In each case, however, the sentence was either suspended by amnesty laws, overturned on appeal or dismissed after the statute of limitations had expired. In one of those delightful paradoxes of Italian life, court decisions can only be enforced when a case is completely adjudicated — including appeals — within a certain time period. In Italy, the statute of limitations is not suspended even if a trial has started. Mr. Berlusconi has two means to fight the charges. The statute of limitations on these charges expire next year, and the wheels of Italian justice move slowly at the best of times. And Mr. Berlusconi also enjoys immunity as a member of Parliament, pretty much ensuring that he will elude justice.