A street is littered with debris after a Saudi-led airstrike against Iran-allied Shiite rebels, known as Houthis, that targeted a site of a weapons cache in Yemen's capital, Monday, April 20, 2015. Airstrikes on weapons caches in Yemen's rebel-held capital on Monday caused massive explosions that shattered windows, sent residents scrambling for shelter and killed a local TV presenter. (AP Photo/Hani Mohammed)

U.N. Helpless As Crises Rage In 10 Critical Hot Spots

Secretary-General Ban Ki-moon says even the U.N.’s 193 member states cannot, by themselves, help resolve these widespread conflicts.