It will be a long while before the ultimate legal fate of former President Lee Myung-bak is determined, as the fight between the prosecution and Lee is almost certain to continue to the Supreme Court.

The first round of the battle is set to start Thursday, when the court arraigns Lee at the prosecution’s request to detain him on a total of 18 charges. The court’s decision may set the tone for the upcoming legal fight between prosecutors and Lee and his defense attorneys.

Whatever decision the court may make, the nation should draw some lessons from the latest in a series of corruption cases involving former presidents.

Most of all, the Lee case has shown -- once again -- how vulnerable the Korean presidency is to corruption and other misdeeds. Lee is the fifth former president who has faced prosecution for past wrongdoings. More shameful is that there is already one former president incarcerated for corruption. The first court ruling on the case of the ousted president, Park Geun-hye, is set for April 6.

Like the Park case, all the charges raised against Lee have yet to be judged by the court, but what the prosecution has listed in its arrest warrant request should surprise many.

Lee is suspected of having taken 11 billion won ($10.3 million), including money from the secret, audit-free “special activity account” of the National Intelligence Service, similar to a charge his successor Park Geun-hye faces.

He is suspected of running a slush fund amounting to 35 billion won through an auto parts company registered to his brother but which the prosecution believes he actually owns. The prosecution also has accused Lee’s wife, Kim Yoon-ok, of using a company business card issued by the same company.

Prosecutors said Lee allegedly had Samsung Electronics pay legal fees amounting to 6 billion won when DAS was engaged in a legal suit in the US. Prosecutors suspect that the money was a kickback given by Samsung in return for the special amnesty granted to its chairman Lee Kun-hee.

Besides the cases involving DAS, Lee, according to the prosecution, took money indiscriminately. He took money from an ailing shipbuilder through a top banker, a person who sought his ruling party’s nomination for parliamentary election and a Buddhist monk who wanted to establish a Buddhist college. His wife also is alleged to have taken money from the NIS and a business executive in New York.

Prosecutors say some of the money was given to Lee or people close to him even before the presidential election in December 2007. Those who provided the money must have done so in anticipation of Lee’s victory, as he was the leading candidate.

Again, all charges and suspicions raised against Lee must be reviewed by the court and all evidence must be verified, but there are some grounds to the prosecution’s argument that it needs to detain Lee because of the gravity of the charges.

Prosecutors also argue that Lee’s denial of most of the charges raises concerns that he could try to tamper with evidence if he is not taken into custody. While the court is set to make its judgement on that Thursday, Lee’s defiance has added to the negative public sentiment toward him. A recent public opinion survey found that about 75 percent of Koreans favored bringing Lee into custody.

This, however, should not free the prosecution -- or more broadly the government of President Moon Jae-in -- from criticism that the investigation into Lee has been politically motivated.

Indeed, the prosecution -- which seems to always put priority on investigations beneficial to the government in power -- has been digging into Lee and people around him -- former aides, family members and friends -- for about six months. It is not entirely wrong for Lee to insist that he is the victim of a political vendetta on the part of the Moon administration. Lee has specifically referred to the case of former President Roh Moo-hyun, who took his own life in 2009 in the midst of a corruption probe of him and his family during the Lee administration.

The Lee case should be another reminder that the nation should look for measures to ensure the prosecution’s independence from political power. It is essential for cutting the vicious cycle of former presidents being subject to prosecution whenever a new president takes office.