1945年在旧金山签署《联合国宪章》时，只有51个会员国，连续的世界大战、国际联盟崩溃和一些帝国的瓦解仍在影响世界。
When the UN Charter was signed in San Francisco in 1945, the membership stood at 51. The world was still reeling from the effects of successive World Wars, the collapse of the League of Nations and the collapse of empires.