Like his predecessors, President Moon Jae-in is having difficulty setting his administration into motion due to defects -- mostly ethical ones -- found in the people he has nominated to senior posts.

That we face the vicious circle every time we have a new administration shows that many elite members of society neglect the law in pursuit of personal interests.

It is no exaggeration to say that not a single candidate is free from ethical problems. Even Kim Dong-yeon, a former public official whose personal success story -- progressing from shanty town dweller to minister -- helped his nomination as the deputy prime minister and finance minister draw positive public response was dogged by questions about his military service and wealth.

Ethical problems for candidates are inflicting political damage on Moon, who campaigned with a call for a clean and reformative government. What’s ironic is that Moon asked for the trouble himself, as during the election campaign he had set strict ethical rules on candidates for presidential appointments.

Most of the five nominees who have gone through parliamentary confirmation hearings so far have been accused of breaching at least one of the five points set by Moon -- those on false residence registration, tax evasion, real estate speculation, military service and plagiarism. Moon should have been wiser than believe he would be able to find candidates spotless on all accounts.

Another major problem is that Moon’s vetting team is not doing its job so well. It is apparent the team’s background investigation of candidates for senior posts is as faulty as the candidates.

One prime example is the case of Foreign Minister-nominee Kang Kyung-wha. While announcing Kang’s nomination, Blue House officials “confessed” to the fact that Kang once registered a false residence for her daughter, who has US citizenship.

As it turned out, that was not all. Kang lied about who owned the home to which her daughter had moved her residence, though only on paper. New allegations about taxes and wealth involving her and her family have come out.

This alone shows the Blue House vetting team relies mostly on information provided by candidates themselves when it conducts investigations into their backgrounds.

If facts, some of the ethical problems -- like those of Kim Ki-jung, a senior presidential security aide who offered his resignation only 12 days after his appointment -- would have been checked easily if officials had only made inquiries about their reputation.

Blue House officials said Kim Ki-jung, a vice chief of the National Security Office, tendered his resignation for health reasons as well as gossip about his personal life when he was a professor at a university. But news reports said women’s groups accused Kim of “inappropriate conduct” and they demanded Moon sack him. Interviews with Kim’s colleagues, students and people around him would have led the vetting team to discover this information.

Most presidential appointees are close to the president, which partly makes a thorough check by the Blue House team more difficult. Kim of the NSO and Moon went to the same high school, and he had advised the president since his first presidential bid in 2012.

One possible solution could be for the president and his aides other than those on the vetting team to remove themselves completely from the background investigations into candidates.

In other words, there should be a wall between the president and those who assist his efforts to find candidates for senior posts and those who vet the candidates and decide whether to go ahead with the appointment or not. It is of course essential for the president to guarantee autonomy of the vetting team.

Last but not the least, Moon -- as he did with Kim of the NSO -- should withdraw nominations of some of the candidates whose ethical problems overwhelm their merits. That may damage his nascent presidency, but it would save it from greater troubles like worsening relations with the opposition and the administration’s overall loss in integrity.