BERLIN — We, former defense chiefs of staff for five countries, recently published a booklet containing proposals for a new strategy, as well as a comprehensive agenda for change.

Why is a new strategy needed? the North Atlantic Treaty Organization's current "Strategic Concept" was adopted in 1999, but since then the world has changed dramatically. At that time, NATO was a regional alliance that concentrated on the reactive defense of the Treaty Area. But reaction is no longer sufficient; today's most urgent task is prevention of crises, armed conflict and war, which may require that the primary response be other than by military means.

Moreover, NATO agreed at its conference in Prague in 2002 that it would act "where necessary," thus abandoning the restriction of acting in defense of the Treaty Area alone. Finally, while the lessons learned since the terrorist attacks of September 11, 2001, suggest that none of today's conflicts can be mastered by military means alone, NATO's means are solely military. Thus, any effective future strategy for NATO must include the development and application of other means.