Kenya's decision this past week to send troops over the border into Somalia in pursuit of al-Shabab militants appears to be a major shift in foreign policy. The full extent of Kenya's operations are not yet clear, but the move could radically change the relationship between the two countries.

Implications

For years, Kenya has put up with its anarchic neighbor, Somalia.

Decades of war in Somalia have driven hundreds of thousands of refugees into Kenyan camps near the shared border - straining resources, the environment and - at times - patience.

Kenya has, for the most part, kept its distance from the conflict, but was instrumental in the formation of Somalia's Transitional Federal Government, and hosted the TFG's early institutions until 2005.

But in recent months, a spate of kidnappings in Kenya - blamed on Somali militants - have significantly raised tensions, and threatened Kenya's all-important tourism industry.

The kidnapping of two doctors from the Dadaab refugee camp in Kenya prompted the Kenyan military to finally take action last weekend.

Egara Kabaji, a former spokesman for Kenya's Foreign Affairs Ministry, says he is not surprised by the decision.

"You know Kenya pursues good neighborliness. But this is an actual provocation," he said."And actual provocation must be responded to. And one thing that is very clear to me is that that was the best position to be taken by the Kenyan government. Because you just can't sit back, and watch bandits getting into your territory and actually destroying your economy and you sit back and you say we are pursuing good neighborliness. It doesn't work like that."

Conflicting information

What is confusing about the current operation, however, are the mixed signals coming from both Nairobi and Mogadishu.

Kenya's Foreign Affairs minister has told local and international media that the Kenyan Army has gone into Somalia, while other Kenyan officials deny the border has been crossed.

Omar Osman, a spokesman for Somalia's transitional government, has also denied any incursion has taken place.

"No I can confirm that they are not there. It's our troops, they are Somali forces who were in Kenya receiving training from Kenyan authorities," he said. "And those Somalis who were in Kenya are the ones who have come to our territory to confront al-Shabab. Kenya and Somalia have a common enemy which is al-Shabab. And we are very grateful that we're receiving the assistance of logistical and the support of Kenyan authorities."

A witness near the border with Kenya told VOA he had seen Kenya fighter jets flying in and out of Somalia in recent days.

Al-Shabab, which denies playing a role in the recent kidnappings, is certainly treating Kenya's military maneuvers as a real threat, and has vowed retaliation. The militants claimed responsibility for a bombing the Ugandan capital, Kampala, last year that killed 74 people.

Military interventions and revenge

Somali political analyst Abdi Samad, with Southlink Consultants in Nairobi, says we could see that type of attack in Kenya.

"If Kenya's succeeded to root out al-Shabab from the central and southern part of Somalia then they are obviously going to revenge," said Samad. "Although al-Shabab, they are not the professional soldiers. What they are going to do is only the incident they did sometimes back in Kampala, the same thing they can do here. They can even make havoc inside Nairobi, they can do that. Virtually the country will be at war."

The history of past military interventions in Somalia does not bode well for Kenya's effort.

In 2009, al-Shabab succeeded in driving out Ethiopian armies that had invaded the country two-and-a-half years earlier. The fighting helped bolster support for the al-Qaida-backed militants.

U.S. forces entered Somalia in 1992 - initially on a humanitarian mission. That ended after Somali militiamen shot down U.S. helicopters in a battle in Mogadishu that killed 18 U.S. soldiers.

The Kenyan government says its aim is to make sure that al-Shabab can no longer operate inside or near Kenya's border. So far there has been no indication of just how long that operation may take.