In the memo, the president said he will “strongly consider” providing military, police and civilian personnel to support or participate in U.N. peace operations.

There are caveats. The direct personnel support would happen only if the need is in a capability in which the United States has specialized expertise and only if U.S. personnel provide the potential to improve substantially the overall effectiveness of the U.N. mission. The deployment cannot adversely impact current or projected U.S. operations elsewhere.

The president would not relinquish command of any U.S. forces deployed to peacekeeping operations, the memo says, but it notes that as commander in chief, he has the authority to place U.S. forces under the operational control of a foreign commander when doing so serves U.S. national security interests.

The increase in support to the United Nations is needed, given the critical U.S. national security interest in propping up weak states and preventing, containing, and resolving armed conflict, the memo states.

Libya, Syria and Somalia are examples of failed states, and there are dozens of fragile and conflict-affected states.

“Their numbers are now rising globally, and may continue to do so over the next decade or more,” the president said in the memo. “Left unassisted, many of these fragile states, where conflict festers and development stagnates, could become hosts of violent extremism; afford safe havens that transnational terrorists and criminals exploit; generate large flows of refugees and displaced persons that can destabilize neighboring countries and sow regional instability; create humanitarian emergencies; facilitate the spread of pandemic disease; and increase the risk of mass atrocities.”

The peacekeeping operations span the spectrum of conflict prevention, peacemaking, and peacebuilding interventions authorized by the U.N. Security Council.