Art. 79 requires an ‘impediment beyond his control and that he could not reasonably be expected to have taken the impediment into account at the time of the conclusion of the contract or to have avoided or overcome it or its consequences’. Drawing a line between the different elements of this provision is not always easy but fortunately not really necessary since the lack of any of these elements denies the promisor exemption under this provision.
(1) Impediment Beyond Control
The basis for the seller’s exemption under Art. 79 is an impediment beyond control that hinders the seller from performing as required by the contract. Examples include events of force majeur like natural (fires, droughts, floodings, earthquakes, epidemics etc.) or man-made disasters (war, revolution, uprisings, terrorist attacks, etc.).
(2) Could not have been Taken into Account
The seller cannot rely on Art. 79 with regard to impediments it could reasonably be expected to have taken into account when the contract was concluded. Relevant here is what a reasonable third person in the shoes of the specific promisor could have foreseen. The idea behind this element is that a promisor that is aware of a certain impediment when negotiating a contract can limit its liability accordingly or alternatively refrain from concluding the contract altogether. Examples for impediments that have to be taken into account are force majeur events that either occur regularly (e.g. Siberian harbors freezing up in winter) or at the time of contract conclusion are already looming ahead in a way that a reasonable person would have taken them into account (e.g. a military coup that is threatening). Other examples are import or export restrictions that certain countries regularly enforce.
(3) Could not have been Avoided or Overcome
Being unable to foresee the impediment at the time of contract conclusion is not enough to exempt the seller from liability. The seller further has to take action to avoid or overcome the impediment and its consequences once it becomes aware of it. Many situations discussed under this heading are already excluded by virtue of the contractual allocation of the procurement risk (e.g. the seller’s duty to procure goods if one of its suppliers does not deliver as agreed).