But while insecurity created by Boko Haram in Nigeria and Cameroon, for instance, or by the Shebab in Somalia and parts of Kenya and Uganda, is plainly worrying, the United States is wary about greatly increasing direct military support to beleaguered governments.
Instead, experts say, Washington prefers to support multinational African forces like those of the African Union (AU), which, despite problems, are seen as more transparent than many national armies.
Obama has said the summit -- a first-of-its-kind meeting which opens on Monday -- will provide a forum to "talk to Africa about security issues".
The goal is to work with "strong partners" that have "pretty effective security forces," saving the US military money and helping keep Americans "safe over the long term," he said.
But such strong partners are not always available, and analysts say that if the United States hopes to have an impact in the continent's hot spots it will have to work with some of Africa's most troubled militaries.
Just hardware and money, please
American officials have for years said they are willing to help Nigeria combat Boko Haram, whose uprising has killed more than 10,000 people since 2009.
But the group's kidnapping of more than 200 schoolgirls in April grabbed the world's attention -- including that of US First Lady Michelle Obama -- and spurred America in May to offer military and intelligence support.
Nigeria accepted the offer, but evidence suggests that Abuja was not particularly interested in operational help or training, said John Campbell, a former US ambassador to Nigeria, who is now with Council on Foreign Relations.
"Please drop off some hardware. Please write a cheque," was a likely Nigerian response to US defence and FBI experts who landed in Nigeria, a country with a decades-long history of corruption, Campbell told AFP.
Aside from marginal training and surveillance assistance, the ex-ambassador said he had seen "almost nothing" emerge from the new cooperation.
For Campbell, the question facing US policymakers is: does Nigeria's military, which has a grim human rights record, "want help from outsiders or not?"
An example 'to build on?'
Aside from relentless attacks in war-torn Somalia, Shebab insurgents have killed civilians across east Africa, including bombings in Uganda's capital in 2010 and gun attacks in Nairobi's Westgate shopping centre last year.
The US provides logistical, training, intelligence and financial assistance to the African troops fighting in Somalia.
It is the type of intervention the administration would like "to build on," Deputy National Security Advisor Ben Rhodes said ahead of the summit.
He added that the US remained "concerned about efforts by (international) terrorist groups to gain a foothold" in Africa, even if many analysts saw groups like Boko Haram and Shebab as being domestically focused with almost no intention of plotting attacks on American soil.
While the AU mission against the Shebab has been credited with barring the insurgents from over-running Somalia and keeping the fragile Western-backed government in power, the pan-African force has also been subject to controversy.
Salaries for soldiers on the ground have reportedly been pocketed by commanders and there is speculation that weapons meant for peacekeepers have ended up in Shebab hands.
The force is led by troops from Uganda, a country whose once-close relationship with the US has deteriorated.
The Ugandan military has always been tightly controlled by President Yoweri Museveni and his loyalists, who are accused of looting tens of millions of dollars of US foreign aid since taking power in 1986 and using the army to crack down on political opponents.
An anti-homosexuality law, which US Secretary of State John Kerry has compared to Nazi-era measures, has intensified scrutiny of all US support to Kampala.
A Ugandan court struck down the law this week, but Museveni's allies say it remains intact and could be reinstated on appeal.
An elusive warlord
A small detachment of US special forces have been based in the Obo region of the Central African Republic since 2011, helping hunt for Lord's Resistance Army (LRA) commander Joseph Kony, who is wanted by the International Criminal Court.
Kony, who launched his rebellion in northern Uganda in the late 1980s, has been forced out of his home country, but Ugandan troops are still on his trail.
US National Security Advisor Susan Rice said killings by the LRA have fallen 75% since the US formally joined the Kony hunt in 2010.
Former ambassador Campbell agreed that the LRA mission could be seen as a success story for the US in Africa, even if the ultimate goal remains unfinished.
"The last time I looked, Joseph Kony was still at large. On the other hand the depredations appear to be over," he said.