NAIROBI, Kenya — The third kidnapping of foreigners in Kenya by suspected Somali gunmen in less than five weeks proves that Kenya cannot isolate itself from the chaos in neighboring Somalia where 20 years of civil war and lawlessness have spawned violence, piracy, famine and kidnapping.

Somalia’s woes spill across its borders, with increasingly dangerous repercussions for Kenya, which shares 400 miles of largely unpoliced frontier and is heavily reliant on tourist income, its biggest foreign exchange earner.

“The idea that Somalia’s problems can be contained across the border is out of date,” said Roger Middleton, Horn of Africa researcher at London’s Royal Institute of International Affairs. “These kidnappings are really worrying for Kenya and can cause enormous problems.”

On September 11 a British man, David Tebbutt, was shot dead and his wife Judtih, 56, kidnapped by gunmen who came on boats and attacked the couple at a luxury resort in Kiwayu on Kenya’s northern coastline.

Three weeks later Marie Dedieu, a 66-year old wheelchair-bound French woman, was taken from her rented home on the island of Manda just across a narrow channel from the popular coastal tourist town of Shela on Lamu Island.

Then on Thursday came the abduction of two Spanish women working for the international medical charity Medecins Sans Frontieres (MSF) who were seized at gunpoint inside Dadaab, a wind-swept city-sized sprawl of refugee camps in Kenya’s inhospitable northern wastelands.

Their driver was shot and wounded and their MSF-branded 4x4 was comandeered by the kidnappers who sped off in the direction of the Somali border 60 miles to the east.

GlobalPost in Kenya: 2 Spanish aid workers kidnapped

Soon after the attack Leo Nyongwesa, the provincial police chief, said a manhunt had been launched. “We are following them by the road and air. We have closed the borders. We are tracking them down,” he said on Thursday.

In reality the border cannot be closed as it runs unpoliced and unfenced through harsh desert and scrub.

By Friday morning, with no rescue carried-out, Nyongesa was telling reporters that it seemed clear the kidnappers had indeed crossed into Somalia. The stolen car was found abandoned 12 miles from the border.

Dadaab refugee camp is at the heart of one of the world’s largest humanitarian relief operations in response to a regional drought and a famine in some parts of southern Somalia.

Since the kidnapping of the two aid workers some charities and United Nations agencies have confined their staff to fortified compounds. Others are mulling whether to pull foreign staff out or scale back activities that are not directly related to saving lives.

Just as a massive suicide truck bomb in Mogadishu earlier this month made aid workers more wary of helping the tens of thousands who have sought food, medical care and shelter in the Somali capital, so this kidnapping will hamper the relief effort in Dadaab which is now home to around 450,000 people.

Tourism and the charity industry both contribute to Kenya’s economy.

Kenya is a regional hub for aid agencies and benefits from the presence of so many charities working to alleviate the Somali refugee crisis. Aid agencies import vehicles, rent premises, hire staff, buy visas and pay taxes all of which brings foreign currency into the local economy.

The figures for tourism are easier to add up: Kenya received over 1 million tourists last year; the industry brought in more than $800 million making it the third biggest earner after tea and horticulture. Kenya cannot afford the spread of insecurity and the fear that goes with it. Hotels in Lamu have had cancellations since the kidnappings began and some have closed, even if temporarily.

The pirates who prowl off Kenya’s coast, and the famine pushing over a thousand Somalis a day into desperate exile in Dadaab’s camps cannot be blamed on Kenya. Nor can the civil war that has raged in Somalia since 1991, its most recent iteration being the brutal battle between Al Qaeda-linked Islamists and the Western-backed government in Mogadishu.

GlobalPost in Kenya: Kidnappings, new Kenyan port threaten historic Lamu

But successive Kenyan governments have shown little but wilful neglect and contempt for both their own ethnic Somali nationals and Somalis from across the border and this has stoked mutual resentment and suspicion.

The Kenyan state has hardly tried, and never succeeded, in projecting either political power or economic benefits from the capital to the northern badlands, a barren region which feels scarcely part of the nation.

A Somali ghetto in Nairobi has become both recruiting ground and rearbase for Al Shabaab whose fighters dissolve among the throng of ordinary people, just as they hide themselves among the refugees in Dadaab.

Rather than targeting the criminals, Kenyan security forces simply pull regular dragnets through Eastleigh rounding up and roughing up people at random.

Nor is this the first time Kenya’s tourism industry has been threatened by violence. In both 1998 and 2002 the country was the scene of murderous Al Qaeda bombings that targeted the United States embassy in Nairobi and an Israeli hotel and airliner in Mombasa.

But not all the threats come from outside. Crime, sometimes violent, is a perennial concern and in 2008 politicians stoked ethnic tensions that turned to slaughter after disputed elections, leaving well over a thousand dead and hundreds of thousands homeless.

Kenya has this year made tentative moves towards greater military engagement in Somalia. It has trained and backed the Ras Kamboni militia which fights the Shabaab on the other side of the border near Dadaab and senior ministers have begun to talk of more muscular intervention to stabilize its chaotic neighbor.

With Somalia’s troubles looking as intractable as ever, it seems inevitable that Kenya will be pulled further into its maelstrom.