Outgoing UN rights chief Navi Pillay has rebuked the UN Security Council for putting short-term geopolitical concerns and narrowly-defined national interests ahead of intolerable human suffering and grave breaches of global peace and security.
"I firmly believe that greater responsiveness by this council would have saved hundreds of thousands of lives," Ms Pillay told the 15-member body during her final briefing after six years as the UN High Commissioner for Human Rights.
She said crises in Syria, Afghanistan, Central African Republic, Democratic Republic of Congo, Iraq, Libya, Mali, Gaza, Somalia, South Sudan, Sudan and Ukraine "hammer home" the international community's failure to prevent conflict.
"None of these crises erupted without warning. They built up over years - and sometimes decades - of human rights grievances," said Ms Pillay, a South African jurist.
She suggested the Security Council come up with possible new responses to rights violations, such as deploying rapid, flexible and resource-efficient human rights monitoring missions that would be limited in time and scope.
Her successor, Jordan's Prince Zeid Ra'ad Zeid al-Hussein, who will start his four-year appointment next month, could also informally brief the Security Council once a month in a bid to strengthen early warnings of potential crises, she said.
Ms Pillay also recommended building on the UN Arms Trade Treaty, which aims to regulate the $85bn arms industry and keep weapons out of the hands of rights abusers and criminals.
"States parties could agree that where there are concerns about human rights in states that purchase arms, one condition of sale would be that they accept a small human rights monitoring team," she said.
The treaty is due to enter into force once 50 countries have presented proof of ratification to the United Nations.
At least 44 countries have so far ratified the treaty.
United Nations Secretary-General Ban Ki-moon said that even modest, early UN action could be important when it had full support from the Security Council.
"However, when there is limited consensus - when our actions come late and address only the lowest common denominator - the consequences can be measured in terrible loss of life, grave human suffering and tremendous loss of credibility for this council and our institution," Mr Ban told the council.
Russia's UN Ambassador Vitaly Churkin said that states have the main responsibility for conflict prevention, warning that any international assistance should be done with the consent of the host country and not imposed.
"Unfortunately in the UN Security Council we have often heard proposals that border on the management of internal affairs of states or even interference into their constitutional procedures," he said.
British UN Ambassador Mark Lyall Grant, president of the council for August, said the body needed "to switch from a culture of reaction to a mindset of conflict prevention."
The council unanimously adopted a resolution expressing determination to prevent armed conflict as part of its primary responsibility to maintain international peace and security.