"Last year in the first ever presidential directive on this challenge, I made it clear that preventing mass atrocities and genocide is a core national security interest and a core moral responsibility of the United States of America. That does not mean that we intervene militarily every time there’s an injustice in the world - we cannot and should not," Obama said, speaking at the Holocaust Memorial Museum.
"It does mean we possess many tools – diplomatic and political and economic and financial and intelligence and law enforcement and our moral swasure. And using these tools over the past three years I believe, I know that we have saved countless lives," he said.
The president pointed to U.S. intervention in Sudan and Libya as examples.
"When the referendum in South Sudan was in doubt, it threatened to reignite a conflict that had killed millions, but with determined diplomacy, including by some people in this room, South Sudan became the world’s newest nation, and our diplomacy continues, because in Darfur, in Abyei, in southern Kordofan and the Blue Nile, the killing of innocents must come to an end," Obama said.
"The presidents of Sudan and South Sudan must have the courage to negotiate – because the people of Sudan and South Sudan deserve peace. That is work that we have done, and it has saved lives," he added.
"When the Libyan people demanded their rights and Muammar Qadaffi’s forces bore down on Benghazi, a city of 700,000, and threatened to hunt down its people like rats, we forged with allies and partners a coalition that stopped his troops in its tracks. And today, the Libyan people are forging their own future, and the world can take pride in the innocent lives that we saved," the president said.
In central Africa, Obama ordered advisors to help Uganda and its neighbors pursue the Lord's Resistance Army, led by Joseph Kony, and the president ordered the National Security Council to review the progress after 150 days.
"We have done so, and today I can announce that our advisors will continue their efforts to bring this madman to justice, and to save lives. It is part of our regional strategy to end the scourge that is the LRA, and help realize a future where no African child is stolen from their family and no girl is raped and no boy is turned into a child soldier," Obama said.
Also, those responsible for war crimes and crimes against humanity have been barred from entering the U.S. for the first time ever.
"We’ve stepped up our efforts in other ways. We’re doing more to protect women and girls from the horror of wartime sexual violence. With the arrest of fugitives like Ratko Mladic, charged with ethnic cleansing in Bosnia, the world sent a message to war criminals everywhere: We will not relent in bringing you to justice. Be on notice. And for the first time, we explicitly barred entry into the United States of those responsible for war crimes and crimes against humanity," Obama said.
The president also signed an executive order authorizing new sanctions against Syria, Iran and their abettors for using technology to "repress" citizens.
"Indeed, today we’re taking another step. I’ve signed an executive order that authorizes new sanctions against the Syrian government and Iran and those that abet them for using technologies to monitor and track and target citizens for violence. These technologies should not empower -- these technologies should be in place to empower citizens, not to repress them. And it’s one more step that we can take toward the day that we know will come -- the end of the Assad regime that has brutalized the Syrian people -- and allow the Syrian people to chart their own destiny," Obama said.