Coordinated international actions to protect the stratospheric ozone layer were implemented after the 1988 Vienna Convention and the 1989 Montreal Protocol. Both instruments are considered a model approach to effective cooperation in combating environmental threats at the global level. The projections indicate that the regeneration of the ozone layer would occur at the turn of the 20th and 21st century. Now it appears that the regeneration process may be delayed by several years as the atmospheric ozone depletion has not been stopped, although its rate has been greatly decreased. The author discusses the reasons underlying this phenomenon.