Although it is clear that a fundamental change of circumstances might justify terminating or modifying a treaty, unilateral denunciation of a treaty is prohibited; i.e. a party does not have the right to denounce a treaty singlehandedly.
If the parties to a treaty had contemplated for the occurrence of the changed circumstance, the doctrine will not apply and instead, the provision will take effect. Clausula rebus sic stantibus only relates to changed circumstances that were never contemplated by the parties. This principle is clarified in the Fisheries Jurisdiction Case; United Kingdom v. Iceland 
Otto von Bismarck said that all treaties should contain this phrase.
European Court of Justice holds that continued fighting in former Yugoslavia fundamentally undermined 1980 preferential customs agreement with Serbia that justified EC Council in suspending it under international law principle of rebus sic stantibus.(Brief Article)
Jun 01, 1999; Between November 1990 and April 1992, A. Racke GmbH & Co., a German firm, had imported wines into Germany from Serbia and had...
Law Report: `Mode or Category' of Occupation Was a Material Factor in Rating Valuation ; 21 February 2001 Williams V Scottish & Newcastle Retail Ltd and Anor Court of Appeal, Civil Division (Lord Justice Aldous, Lord Justice Robert Walker and Lady Justice Hale) 15 February
Feb 21, 2001; PARAGRAPH 2(3) to (7) of Schedule 6 to the Local Government Finance Act 1988 recognised that "mode or category of occupation" was...