( 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 . While there are obviously differences , these situations in the Mideast and Sudan have more in common than the painful process of division . Each features disputes over land and resources , religious and ethnic differences , and conflicting narratives of bloodshed and loss . Time is a critical element in every peace process . And with its referendum fast approaching , Sudan , too , faces the tyranny of the onrushing calendar . The deadline for the Southern referendum promised in the peace agreement , January 9 , 2011 , is not negotiable . But exactly how the North and South will simultaneously separate while remaining interconnected must be . Southern Sudan may possess most of the known petroleum reserves , but the pipelines to market for that oil run through the North . Millions of Southerners displaced by the war will continue to live in Khartoum , and Northerners will live in the South . Every dry season , herders from the North 's Arab Misseriya tribes cross into what will likely become the country of Southern Sudan and then return . The Nile will continue to flow northward , regardless of borders and politics . Boundaries must simultaneously be demarcated and accommodating . And the parties need to finalize the details fast enough to ensure that violence can not fill the vacuum . The last war between North and South lasted for decades and claimed millions of lives . Earlier this year , then-Director of National Intelligence Dennis Blair told Congress that , over the next five years , Southern Sudan is the place where `` a new mass killing or genocide is most likely to occur . '' And while we try to prevent the next potential wave of genocide , we can not ignore the fact that Darfur 's tragedy remains unresolved . Even as America asks how it can help Southern Sudan prepare for the likely burdens of statehood , it must also consider the Sudan that remains . Attention to Darfur must not be a casualty of our necessary fixation on the North-South crisis . Recognizing the urgency of the situation , the administration has launched a heightened campaign of diplomatic engagement . President Obama joined U.N. Secretary-General Ban Ki-moon and Vice President Ali Osman Taha of the North and Salva Kiir , leader of the South , in New York last week to highlight the imperatives of peace , while he has also reinforced the American diplomatic presence in the region . Congress must also weigh in . I have written legislation to put Congress on record to reinforce the American commitment to see the peace agreement through , to lay the groundwork for what will come and to reinvigorate the Darfur peace process . One painful lesson from years of Mideast peacemaking is that even when the elements that will constitute an accord may seem clear from the outside , the compromises and choices that will make it possible are difficult to accept , sequence and execute . Time in Sudan is short and the stakes are high . Although the Sudanese themselves will own their future , America must now help North and South Sudan to find a peaceful path forward . The opinions expressed in this commentary are solely those of John Kerry .
Kerry : North and South likely to vote for independence , raising specter of more war with North . Northerners must commit to laying groundwork for peace between South Sudan , he writes . Senator says the situation resembles Middle East in its complexity and pitfalls . Commitment to revive peace process in South Sudan also essential , Kerry writes .