Afghan presidential candidates Abdullah Abdullah (L) and Ashraf Ghani (R) attend a ceremony after signing a power-sharing agreement at the Presidential Palace in Kabul, Afghanistan, 21 September 2014. (Jawad Jalali/EPA)

John Kerry is secretary of state.

On Monday in Kabul, the Afghan people will inaugurate their next president, one who will work in tandem with the country’s first-ever chief executive officer — marking the first democratic transfer of power in Afghanistan’s history and the first peaceful leadership transition in more than 40 years.

This moment was not easily arrived at, and it belongs primarily to the millions who courageously went to the polls to vote in April and June in defiance of Taliban threats. The voters’ message was unequivocal: No improvised explosive device and no suicide bomber would stand in the way of their country’s democratic future. The moment belongs also to Ashraf Ghani and Abdullah Abdullah, two statesmen who put their country’s interests first and came together to form a government of national unity following a very contentious election.

The United States supported a credible, transparent and inclusive electoral process without favoring any particular candidate. It was precisely because of our clear neutrality and commitment to the Afghan democratic process that both sides invited our support when serious allegations of electoral fraud emerged after the runoff election. Of course we helped the candidates address both the electoral fraud and the potentially dangerous political divide that the candidates were facing, but Afghans and Afghans alone made the tough decisions.

And for those at home who are quick to question Afghanistan’s democracy, they might ask themselves whether they believe that — in less than 90 days — two U.S. presidential candidates could transform a bitter and hotly contested campaign into a unity government with an exceptionally strong mandate to govern. (Flipping the pages of our own history back to the 2000 election, the answer might provoke some humility or at least some perspective on how difficult it can be.) No, the process wasn’t simple. Yes, there were many high-wire moments when it seemed just as likely that Afghanistan’s political future could lurch in dangerous directions. But in the end, statesmanship and compromise triumphed. Perhaps Washington could take a lesson from Kabul.

Where do we go from here? Afghanistan’s new government is built on a common vision for economic reform, honest government, security and peace. Both Ghani and Abdullah ran their campaigns on platforms of inclusive, broad-based government. The government of national unity is their way of honoring those promises.

Those promises must now be met in actions, not words. The tough decisions among Afghans did not end with the unity government or with this inauguration — in fact, they’re only beginning. The Afghan people and their new government face serious economic and security challenges. Continued U.S. and international assistance, along with the economic reforms that Afghanistan’s new political leaders promised, will help the country ameliorate its budget shortfall. President Ghani and CEO Abdullah promised their voters that they would sign the U.S.-Afghanistan Bilateral Security Agreement as one of their first acts in office. It will provide the legal framework for the United States to continue to train, advise and assist Afghan national security forces, so Afghanistan will never again be a haven for terrorists.

But even as the path ahead is challenging, we already have proof of concept that Afghanistan can beat the odds: Just look at the important strides in the past decade. Afghans are living longer and healthier lives, girls are in school and a remarkable free media keeps citizens informed. Afghan troops are fighting and dying for their country, but they are holding ground. Together with the international community, the security and economic assistance we pledged in Chicago and Tokyo will be crucial to that progress in the next decade.

The gains of the past decade — for the security of our country and our allies and in the lives of the Afghan people — have been won with blood and treasure. They must not be lost. I reminded the men who now lead Afghanistan that we were committed to their country for the long haul but that we measured that commitment in our ability to credibly look a combat-disabled American veteran or a Gold Star mother in the eye and tell them that, going forward, Afghans themselves would compromise and govern as selflessly and effectively as Americans fought and sacrificed for them and with them the past 10 years. Our job now is to support Afghanistan for the Afghans — and to stay committed to a country of people who believe in a better future with an inclusive government that serves them all. Even as this political transition concludes and as Afghanistan takes responsibility for its own security, we must continue to support that aspiration.