What is the test for variation in maintenance agreements?

64 The law relating to the variation of maintenance agreements is most unsatisfactory. The so-called trilogy of cases led by Pelech v. Pelech, 1987 CanLII 57 (SCC), [1987] 1 S.C.R. 801 (S.C.C.) was decided in the context of the often unrealistic "clean break" model in which the courts assumed that the economic self-sufficiency of both spouses could and should be achieved as soon as possible after separation or divorce. In Pelech, for example, it was stated, at 853 that agreements made between parties who have "...acted in a mature and responsible fashion to settle their affairs in a financial way..." should not be undermined by courts acting with the benefit of hindsight. It can hardly be said that parties who have failed to provide for drastically changed financial circumstances have acted in a mature and responsible fashion. Nevertheless these early cases provided that a causal connection between changed circumstances and the marriage, which is often difficult to identify in individual cases, was an essential prerequisite to variation.