Original post by MathemagicienThe UN was devised by the Allies of WWII to help subdue the Axis powers. The early constituency of UN included nations such as the Soviet Union and China, which had vastly different political systems than liberal democracies like the US and UK.
One of the first major treaties ratified by the U.N. in 1948 was the Genocide Convention, which nobly sought to punish nations that committed mass murder. One problem - the USSR at the time was headed up by Stalin. Stalin absolutely loved killing political dissidents. In order earn his vote, politicide was dropped from the language on genocide.
The treaty was passed amidst great fanfare, and Stalin and Mao went on to kill tens of millions of political dissidents, and commit atrocities against ethnic Germans and Eastern Europeans in Stalin's case, all in compliance with the treaty. So began the downward slide of the U.N. from an organization intending to promote peace to one that became a powerful propaganda tool for autocrats.
Since the resolution passed in 1948, there have been 55 genocides, and we avoided the problem by not using the word genocide. Ethnic cleansing seems a popular euphemism.
As it stands in modern times, only about 41% of the U.N. member states are free democracies. Each country gets an equal vote in the General Assembly, so in many respects it has become a "Democracy of Dictators".
The U.N. Commission on Human Rights included such human-rights loving nations as: Saudi Arabia, Sudan, Congo, Zimbabwe, China, Pakistan, Cuba, Venezuela and Egypt.
The 5 permanent members of the U.N. security council happen to be 5 of the 7 largest arms exporting countries in the world. No conflict of interest there..
As with any body of dictators, corruption is rife. One example: commanders in the U.N. peacekeeping missions in Cambodia, Mozambique, Bosnia, and Kosovo decided to make a little cash on the side by selling children into prostitution. 16 soldiers were barred from further peacekeeping missions following an investigation confirming this. In other instances, aid money and resources that were voted on by dictators were then kept by other dictators rather than going to their people (surprise!). Yasser Arafat's net worth was reportedly somewhere between $300m to $1.3b.
The U.N. has massively failed at its mission to prevent conflicts. The Srebrenica massacre; one example among many: Serbian troops killed 8,000 Bosnian civilians while 400 armed Dutch U.N. peace keepers watched and did nothing to stop it. To say nothing of UN troops themselves committing attacks on the local population, notably raping local girls.
The constituents of the General Assembly (UNGA) are often openly anti-democracy. In 2012, 80% of the UNGA resolutions targeted Israel (the only liberal democracy in the region) versus one resolution on Syria, despite the fact that the ongoing Syrian civil war has killed over 100,000 civilians.
In short, while the U.N.'s mission comes off as noble, its inner workings reflect the leaders it represents. Rather than a bastion of freedom and democracy, it has become a powerful propaganda tool for the wrong causes, and has demonstrated itself to be useless at preventing genocide and human rights violations.
All stolen from a Nate Anderson from Quora.