Champaign, Ill.

WHILE it is too soon to offer any meaningful perspective about the impact of the WikiLeaks disclosures on American foreign policy, it is not too early to reflect on what the leaked diplomatic cables say about the public’s understanding of how diplomacy works.

WikiLeaks’s justification for releasing confidential State Department materials is that the more the public knows about how our government conducts its foreign relations, the better the outcome will be. This is an old idea: Woodrow Wilson advocated “open covenants of peace, openly arrived at.” But history also shows that open diplomacy is often fatally flawed.

Secrecy is an essential part of any negotiation: no corporate merger, complicated legal settlement, amicable divorce or serious political compromise could ever be reached without a reliable level of confidentiality.

But secrecy is nowhere more essential than in foreign relations. For example, had the various diplomats negotiating the end of the cold war and the unification of Germany had to deal with public revelations of the disagreements, half-baked proposals and reckless language in their internal communications  like Margaret Thatcher’s opposition to German unification versus Helmut Kohl’s determination to achieve it  substantive talks would have been impossible.