As the Ehud Olmert saga has unfolded in recent years, culminating in his prison term beginning Monday, many Anglo-Israelis have recalled another leader’s fall from grace - president Richard Nixon.

Even though the crimes of the two leaders are impossible to compare, it’s interesting to look at how one of them walked away to private life and the other ended up in jail.

The simple answer is that Nixon was pardoned and Olmert was not. Nixon never faced the charges against him in court and Olmert did in the most graphic and drawn out manner one could imagine.

But that again raises the questions of why? Was it something different about Nixon and Olmert personally, something different about their crimes or differences in the Israeli and US systems? Or was it changes brought on in the 40 years between the crimes? Undoubtedly there were personal differences. Olmert always wanted to be loved and respected and tried to maintain his legacy even hours before entering prison, which meant exposing himself and confronting the charges (though he did initially push to delay the trial until after his term.) Nixon was paranoid that the world hated him and was against him no matter what he did, and always preferred secrecy to exposure to the public eye.

He went so far as to effectively force the resignations of the US attorney general and his deputy, until he found an official who would fire the special prosecutor who was subpoenaing him.

There is also the matter of the secret tapes – Nixon destroyed his, Olmert’s were aired by someone else without knowing they existed.

Their crimes were different, but if anything, Nixon’s were committed while he was president and he abused his presidential powers to sabotage the Democrats and then used federal agencies to try to cover up his crimes.

Olmert’s crimes took place before he became prime minister and at the end of the day came down to bribery and fraud whose harm to society was far more indirect.

But another answer lies in differences in the respective countries’ systems of government – Israel is a parliamentary democracy and the US is a presidential democracy.

There are some other unique features to Israeli democracy, says Solon Solomon, a former Knesset legal adviser now a visiting lecturer at King’s College London Dickson Poon School of Law. He says that many other democracies would not let the police investigate a head of state for most crimes until after he has left office.

Notably, Olmert had to step down to confront a special proceeding for questioning Morris Talansky before Olmert was even indicted about funds he gave him.

In Israel, the prime minister has no power to pardon, says Solon. The president, a separate office, does. So Olmert could not just appoint a replacement to pardon him as Nixon did in appointing then- Vice President Gerald Ford.

Further, while Israeli prime ministers often assign a designated caretaker in case he is incapacitated, that caretaker is not guaranteed any time in office like a US vice president who replaces a president who is either assassinated or unable to perform his or her duties.

The bottom line is that Nixon was able to stack the deck to ensure his own pardon and Olmert could not.