Something like 33% of marriages end in divorce within a 15 year period. The number of divorces is highest among men and women aged 40 - 44. Marriages last on average for a little over 11 years. we talk of marriages that end in divorce as having 'failed'. But is the success of marriage best judged by its endurance? Perhaps there is a better measure of success.
Divorce is not an easy process. Half of couples divorcing having children under 16. David Cameron is pledged to 'strengthen families' by making it tougher to get a divorce. The Tories see the 'breakdown' of marriage as symptomatic of a 'broken society'. But making it more difficult to divorce may not be the best approach to dealing with the collateral damage of divorce; indeed it may make it worse.
We talk of marriages as having 'failed' if they end in divorce; but marriages don't fail simply because they come to an end. Even a successful marriage might end if one or both people in it change; and people do change. Or at least what they might want changes. The marriage may have been successful in fulfilling the social union between the couple concerned, it might have achieved success with children and seeing them through their early development. The demands of life change with time, with jobs, with promotion or unemployment, with moving house, with stress and these may bring unexpected responses or affects on those involved. Even having children may have an unexpected outcome.
There is no manual for dealing with this. The expectation that marriage is a life-long commitment may not in most circumstances be sensible. The social and economic conditions for marriage as a social institution have changed. "Till death us do part" regardless of context isn't necessarily the best road to happiness. Even a successful marriage may end in divorce with changing circumstance.