(CNN)  -- As the United States works with Israelis and Palestinians to sustain Mideast peace talks, another diplomatic effort to forge a two-state solution is quietly but quickly moving to the center of American foreign policy. In about 100 days, the people of South Sudan are to vote on whether to declare independence from the government in Khartoum. That deadline was set when the two sides signed the Comprehensive Peace Agreement of 2005, which promised this option. There is little suspense as to the outcome: Every reliable source indicates that South Sudan will vote for separation, dividing Africa's largest country and taking with it some 80 percent of known Sudanese oil reserves. No, the critical choice that leaders in both North and South face is between a future of peaceful coexistence or a return to chaos and war in a place tragically familiar with both.
@highlight
John Kerry: South Sudan likely to vote for independence, raising specter of more war with North
@highlight
Congress must commit to laying groundwork for peace between North and South, he writes
@highlight
Senator says the situation resembles Middle East in its complexity and pitfalls
@highlight
Commitment to revive peace process in Darfur also essential, Kerry writes
And while we try to prevent the next potential wave of genocide, we cannot ignore the fact that @placeholder's tragedy remains unresolved.