The increased rates of divorces do not surprise anyone in the Western societies. The rise is believed to happen due to a number of legal, social, economic and cultural changes which happened for the last fifty years.
Divorce as breaking up the marriage on the consent of the spouses came into legal practices after 1970 in the US. Before that time, it was necessary for a spouse to be criminal in order to get a divorce. There was no such thing as a no-fault divorce when spouses could part due to their own wish as if was just unacceptable by the old social norms.
Society changed along with the law, and the feminist movement contributed to the rise in divorce rates. By the end of the twentieth century, many women were employed and did not need allowances from their husbands. Some women considered marriage as an insult to their personal independence. As the power of the institute of marriage dropped, cohabitation came in vogue.
Apparently, the rates of divorce increased as people became less religious. Being bound by spiritual norms, individuals would not dare to break them in the early twentieth century. Over the time, however, people became concerned with more mundane things and religion receded into the background.
Taking into account modern realities, people ceased to treat divorce like something extraordinary. Psychologists blame the lack of commitment in relationships which certainly takes place. Perhaps, couples became too lazy and exhausted to cope with the difficulties which arise in the relationships. It is easier to get a divorce (especially having no children yet) than to entangle the tight knot of mutual insults.