The CNS chairman, who staged the September 19 coup that toppled former prime minister Thaksin Shinawatra, also gave his personal assurance that the military officers - some of them his close associates - would uphold the public interest above all else. He also insisted that the decision, reached in consultation with interim Prime Minister Surayud Chulanont, had been made in good faith.

It was not exactly the kind of explanation members of the public expected to hear. The fundamental question as to what these military men, who lack a business background, can do in profit-oriented state enterprises that civilian professionals with relevant expertise cannot do better, remains unanswered.

Senior military officers took the chairmanships of five major state enterprises - TOT, CAT Telecom, Thailand Post, Bangkok Mass Transit Authority and Port Authority of Thailand, not to mention several others who serve as directors on the boards of many state enterprises. Each of these state enterprises - with a huge organisational structure, complex business processes and billions of baht in annual business turnover - requires its non-executive chairman to be at least a business-savvy person who can develop a smooth working relationship with the company's CEO and other members of the board.

It might well be true, as Sonthi asserted, that military officers could learn about the relevant business models and technologies of the state firms they will be serving. But surely there is a limit to how much these officers, whose main business is national security, can learn.

The non-executive chairman of a state enterprise has the power to set the agenda, guide the board and influence the CEO's decisions. Judging from the performance of previous generations of military officers who served on the boards of state enterprises, the scepticism expressed by many people seems justified. Having military men as chairmen or board members of state enterprises neither reduced corruption nor guaranteed that public interest would be upheld. If the past is any guide, too many officers end up learning the wrong things and becoming more corrupt than they were before. Besides, professional soldiers are not supposed to be put in positions where they might be tempted by the trappings of power and monetary rewards.

What society wants from Sonthi is not his personal guarantee of the integrity and probity of the military men assigned to serve on state enterprises' boards. What we need is a good system to screen and select government officials, including military officers, to serve on state enterprises, based on qualifications, expertise and suitability. We do not need a preferential system of selection based on personal connections, which, in a way, is disturbingly similar to the corruption-prone cronyism practised by former prime minister Thaksin Shinawatra.

Indeed, various government agencies, such as Office of the Civil Service Commission and the Finance Ministry, are already working on criteria to create lists of "public-sector executives" from among highly qualified senior government officials who have demonstrable skills and expertise in different areas of specialisation. Candidates to serve on state-enterprise boards as representatives of the government must be  from these lists to ensure transparency in the selection process.

Sonthi chose to fill these positions in key state enterprises with his trusted friends and subordinates. Now he, and the officers he assigned, must prove beyond any reasonable doubt that they will do their utmost to uphold the public interest, and not seek personal gain. And because they were appointed under extraordinary circumstances, they should voluntarily vacate their positions as soon as the one-year term of the Surayud government and Sonthi's CNS expires, to enable the future elected government to appoint its own representatives to the state-enterprise boards through a more transparent process.