If some Kenya attackers are American, is the US obliged to do something?

US officials are not confirming reports that 'two or three' Americans were among the Kenya mall attackers, but if it is true, it could have legal and security implications for the US.

Kenya’s foreign minister said Tuesday that “two or three” Americans were involved in the deadly mall attack that has left 62 people dead, 175 injured and dozens still missing.

The Kenyan official, Amina Mohamed, told PBS that the Americans were 18 to 19 years old, of Somali or Arab origin, and lived "in Minnesota and one other place" in the US.

With the standoff in its fourth day, US officials are not confirming that report. The FBI, which investigates crimes against Americans and US interests overseas, has been unable to verify it, according to ABC News. And a State Department spokeswoman, Jen Psaki, did not back it up.

“We have no definitive evidence of the nationalities or identities of the perpetrators at this time,” Ms. Psaki said, per The New York Times. “We will continue to look into these reports.”

But if those assertions are true, several questions arise. The basics, of course: Who are they, where are they from, and why have they turned to violence?

It’s a reminder for many that democracy and freedom, even in nations like ours that aim to nurture both intensely, are at times tenuous ideals. Our obligations to those principles don’t end at our border, says Michael O’Hanlon, a Brookings senior fellow who also directs the organization’s foreign policy research.

“I guess it just goes to show that, while we’re pretty lucky not to have large numbers of radicals on our own soil, at least not of a Takfiri/jihadist variety, we aren’t immune to the problem,” Mr. O’Hanlon says. “It also underscores that we may have some obligations to other countries if we contributed to Kenya’s tragedy indirectly, meaning that our overseas military and security activities, we should remember, are not just acts of altruism.”

With the US focused since 9/11 on beefing up institutional practices in place to prevent individuals who mean to harm Americans from getting into the country, this latest episode raises new questions about how we examine those exiting as well.

“Our immigration system may need to look at people more carefully sometimes when they go out of the country, not just when they come in,” O’Hanlon says.

And what of the legal implications of the potential involvement of American citizens in a mass attack in another nation? Again, if the report out of Kenya is true, and the individuals involved survive and are apprehended, where would they be prosecuted? Here, there, or by an international court?

International law specifies two key types of jurisdiction in situations that resemble the one in Kenya, one is territorial, the other nationality-based, according to William Burke-White, a deputy dean and professor at the University of Pennsylvania Law School. As a result, he says, these Americans could be tried in the US or Kenya.

“I would strongly suspect they would be tried in Kenya,” Professor Burke-White says, noting that there is a general preference under international law for territorial jurisdiction.

Kenya has a “difficult” relationship with the International Criminal Court, he adds, saying that venue is an unlikely one for justice in this circumstance. He highly doubts the Kenyans would send an American there for prosecution.

Burke-White called the Kenyan justice system “strong and stern.”

Kenya does have the death penalty, but in 2009, Kenya’s president commuted the death sentences of 4,000 people on death row to life in prison. Kenyan law requires the imposition of the death penalty in cases of armed robbery, murder and treason, Time magazine reported that year, but no one has been hanged there since 1987.

The president at the time, Mwai Kibaki, said that as a result of the lack of action being taken to fulfill their sentences, he aimed to “ease the mental anguish” of those situated on death row. His declaration was greeted with “skepticism” because of the notoriously dismal life – “horrifying,” Time called it – for those confined to Kenya’s prisons. Many instead saw the decision as an effort to get the human rights community off his back.

Meanwhile, The New York Times writes about the generally decent working relationship between the Kenyan government and the US. Kenya’s security forces work in tandem with Western forces to tackle insurgent Islamist actors in the area, the paper reports, and the city’s capital is “an important base for Western embassies and businesses.”

The Somali-based Islamic extremist group claiming responsibility for the attack, Al Shabab, pushed back Tuesday against foreign minister Mohamed’s statement. In addition to the Americans noted, she had mentioned that a British citizen was also involved in the siege.

"We have communicated with our mujahideen in Westgate and they told us fighting has just started," Al Shabab's media office told Reuters. "Those who describe the attackers as Americans and British are people who do not know what is going on in Westgate building."

The US government and the world awaits an end to the incident, as concerns build that some of the perpetrators might have escaped the mall and that the attack there might not be a stand-alone event.