If you say that something is imminent, especially something unpleasant, you mean it is almost certain to happen very soon.
There appeared no imminent danger...
ADJ
• imminence
The imminence of war was on everyone's mind.
N-UNCOUNT: usuNofn
Википедия
Self-defence in international law
Hugo Grotius, the 17th century jurist and father of public international law, stated in his 1625 magnum opus The Law of War and Peace that "Most Men assign three Just Causes of War, Defence, the Recovery of what's our own, and Punishment."