It provides an important buffer of stability in a region that includes the fledgling Somali government and the politically tense Sudan and South Sudan.
Most importantly -- at least to the West -- Kenya is a major U.S. ally in the war against Islamist militants in the region and has remained relatively peaceful amid civil wars in neighboring nations.
Kenyatta's victory raised the prospect of complicated diplomatic ties with the West.
The International Criminal Court indicted him for allegedly funding a local militia that conducted reprisal attacks in the last election in 2007. His running mate, William Ruto, also faces ICC charges at The Hague.
Both have denied the charges and have said they will cooperate with the court to clear their names.
The assurance has not allayed fears among some Western diplomats.
Before the election, Johnnie Carson, the State Department's top diplomat for Africa, issued a stern warning, saying Kenyans can pick their own leaders, but "choices have consequences."
But in a statement after the election, U.S. Secretary of State John Kerry applauded the vote.
"Kenya has been one of America's strongest and most enduring partners in Africa," Kerry said. "We ... will continue to be a strong friend and ally of the Kenyan people."
The UK minister for Africa, Marks Simmonds, echoed his sentiment and called on candidates to address disputes in court to avoid violence.
Kenyatta has said the indictment will not affect his ability to do his job and urged the international community to respect the will of Kenyans.
"I have been a member of the government, and I've still been able to execute my duties," said Kenyatta, a deputy prime minister in the outgoing administration. "I still believe I will be able to execute my duties as president."
Carson's predecessor, Jendayi Frazer, said she does not foresee much change in ties between Kenya and the United States.
"Kenyatta knows that he needs the United States, and the United States knows it needs Kenya," she said. "And so I suspect that while it might be awkward, there won't be a significant change in our policy stances toward Kenya or theirs toward us."
No faith in the ICC
Analysts say the ICC indictment may have rallied citizens to Kenyatta's side in defiance of the West.
"Many Africans have lost faith in ICC and view it as targeting African leaders and failing to discharge its justice among non-African leaders," said Ayo Johnson, director of ViewPoint Africa. "Kenya sent a loud message to the ICC ... don't interfere. And it does not matter if you brand our leaders as criminals."
The president-elect's trial is scheduled for July while his running mate's is in May.
Kenya is the second African nation after Sudan to have a sitting president facing charges at the International Criminal Court.