The VIGILNAT plan is based upon an analysis of the risk of terrorist acts which combines a process to evaluate the threat with identification of the vulnerabilities. This approach enables the VIGILNAT position to be adapted to the current situation.
The plan sets out measures of vigilance, prevention and protection for each of the four alert levels that correspond to the respective threat levels.
Irrespective of the current level of alert, the population should always follow basic security advice.
Alert level 1 corresponds to the LOW threat level
This level does not bring about specific measures, the measures and procedures in place are permanent ones: protection of mass gatherings (in open places) and installations and buildings (places contained within a barrier).
Alert level 2 corresponds to the MEDIUM threat level
This level triggers the implementation of temporary measures of vigilance, prevention and protection of variable intensity that do not excessively limit the country's economic and social life.
Alert level 2 differs from alert level 1 by the implementation of additional and more restrictive temporary measures that are not in principle intended to apply to the whole territory, but instead should be targeted (to a geographic area, a sector of activities or objects) and temporary in nature.
Alert level 3 corresponds to the SERIOUS threat level
This level triggers a reinforcement of measures of vigilance, prevention and protection for vulnerable areas as well as a placing the emergency services on alert.
Alert level 4 corresponds to the VERY SERIOUS threat level
This level includes additional strengthening and mobilisation of all the available forms of intervention, including the army, the application of particularly restrictive measures to counter the threat and, in the event of an attack, to intervene in a rapid, coordinated manner. This level also requires the emergency services to be placed on alert.
Information on the present threat is highly sensitive and therefore not directly available to the wider public. In addition, he authorities will only release information on the measures taken that will neither assist nor direct groups or individuals liable to prepare acts of terrorism. However, it must be noted that the security framework, which includes the visible presence of law enforcement on the ground and checks and searches of people and infrastructures, triggers the four alert levels and upgrading or downgrading from one level to another.