Efforts to expand Security Council membership have failed because countries cannot decide on how it should be done.

The United Nations Security Council is one of the six main organs of the UN, charged with ensuring international peace and security. It has 15 members, but only five of them - the United States, Russia, China, France, and the United Kingdom - are permanent and have veto power.

Efforts to expand the Security Council have been ongoing for decades. The main argument for expansion is that the current membership does not accurately represent the world's geopolitical realities. For example, Africa and Latin America have no permanent representation, and emerging powers like India, Brazil, and Germany are not permanent members.

However, these efforts have failed because countries cannot agree on how expansion should be done. There are several contentious issues:

1. Veto Power: Should new permanent members have the same veto power as the current ones? This is a contentious issue because the veto power is seen as a major source of inequity within the Security Council.

2. Selection of New Members: Which countries should be added as new permanent or non-permanent members? There is no consensus on this, with different countries and