By Adrian Croft and Mirwais Harooni
BRUSSELS/KABUL (Reuters) - NATO will declare "mission accomplished" this week as it winds down more than a decade of operations in Afghanistan but departing combat troops look likely to leave behind political turmoil and an emboldened insurgency.
The embattled country is also suffering a sharp economic slowdown.
NATO had hoped its summit in Wales on Thursday and Friday would herald a smooth handover of security at the end of this year from the NATO-led International Security Assistance Force (ISAF) to Afghan forces. It then plans to cut back its role to a smaller mission to train and advise Afghan troops.
The 28-nation alliance had also hoped to celebrate Afghanistan's first democratic transfer of power by inviting a new president to share the spotlight with U.S. President Barack Obama and the other 27 allied leaders.
Instead, NATO diplomats privately admit that the backdrop to the summit is the "worst case scenario".
A dispute over a presidential election marred by alleged fraud has created a political vacuum which has sown doubts over whether NATO will have a legal basis for leaving any troops in Afghanistan at all after this year.
NATO diplomats were left guessing for weeks about who would represent Afghanistan at the summit. In the absence of a new president, outgoing President Hamid Karzai is staying away, leaving Defence Minister Bismillah Khan Mohammadi to represent Afghanistan.
Sending a lower-level representative rather than a new president will undermine Afghanistan's ability to argue for future Western financial assistance, a U.S. official said.
SECURITY
NATO Secretary-General Anders Fogh Rasmussen put a brave face on the situation at a Brussels news conference on Monday, declaring NATO had achieved its goals in Afghanistan.
"We have done what we set out to do. We have denied safe haven to international terrorists. We have built up capable Afghan forces of 350,000 troops and police. So our nations are safer, and Afghanistan is stronger," he said.
But despite suffering heavy casualties and spending vast sums in Afghanistan, NATO has failed in its key goal of bringing security to the country, some analysts say.
On NATO's watch, there has been a "marked and measurable deterioration of security", said Graeme Smith, senior analyst at the International Crisis Group (ICG) think tank in Kabul.
NATO has also faced criticism over civilians killed in air strikes or night raids.
Kabul residents nonetheless worry that the departure of foreign forces could lead to worse violence or the return of the Taliban, ousted from power by a U.S.-led invasion in 2001.
"We need foreign forces in our country for more years," said Sayed Najibullah Hashimi, a hotel owner in Kabul. "There are lots of improvements since they are in Afghanistan but, as Afghanistan is not on its feet yet, we need them for longer. Their departure means a start of another civil war, more emigration, and economic collapse."
Mohammad Rabih, 27, a student in Bakhtar university in Kabul, said the NATO-led mission had been successful at first but ultimately failed due to the lack of a plan and friction between Afghan and U.S. officials.
"If international forces leave this country, it will turn to a stronghold for Taliban and warlords and not only Afghanistan but the world will pay for that," he said.
Afghan army Brigadier-General Asif Bromand, who heads a busy military hospital in the restive eastern province of Paktia, told Reuters last month it was too early to transfer security responsibilities to Afghan forces. "In each and every aspect, the Afghan army isn't ready," he said.
SHIFT IN TACTICS
The United States intervened in Afghanistan to deny al Qaeda a sanctuary after the September 11, 2001, attacks. NATO -- the North Atlantic Treaty Organization -- took a peacekeeping role in Kabul in 2003, gradually extending it throughout the country.
Over the past 13 years, at least 16,000 civilians, nearly 3,500 foreign troops and thousands of Afghan soldiers and police have been killed. In the first six months of 2014, civilian deaths and injuries due to the war were up 24 percent over the same period last year, according to the United Nations.
ISAF now commands some 44,000 troops from 48 nations, some of which are not NATO members.
The Taliban, kicked out by the U.S. forces, has fought back through a fierce insurgency and still poses a major threat now that Afghan soldiers have taken the lead role for security.
No longer pinned down by U.S. air cover, Taliban fighters are attacking Afghan military posts in larger numbers with the aim of taking and holding ground, a shift from hit-and-run strikes with posses of gunmen, explosives and suicide bombers.
Last month, a U.S. general was killed and more than a dozen people, including a German general, were wounded in an insider attack by an Afghan soldier.
ICG's Smith said Afghanistan had seen improvements in health, education and the economy since the U.S.-led intervention "but the problem is that if you have a clinic in a remote outpost that gets taken over by Taliban then it is not a lasting improvement."
There are also worries over the economic impact the departure of foreign troops will have.
Economic growth slowed from 14.4 percent in 2012 to an estimated 3.6 percent in 2013 due to weaker consumer and investor confidence as the country braced for the political and security transition, according to a World Bank report in April.
The United States alone has spent $103 billion on rebuilding everything from hospitals to security forces in Afghanistan, but Kabul's modest finances make it unlikely it can afford to maintain the projects in the future, a U.S. watchdog said in May.
The deadlock over the presidential election calls into question whether NATO will be able to go ahead with its plans to keep a smaller training and advisory mission in Afghanistan, called "Resolute Support", after the end of this year.
U.S. and NATO officials say foreign troops cannot stay unless the Afghan government signs two agreements providing a legal basis for them to do so.
Karzai has refused to sign. Both warring presidential candidates, Ashraf Ghani and Abdullah Abdullah, say they would sign. However, if the election deadlock drags on much longer, NATO officials say they may be forced to take a decision to pull out NATO troops altogether at year-end.
A senior NATO diplomat, speaking on condition of anonymity, said this week that a decision on a complete pullout would have to be taken about a month after the summit, if the legal documents had still not been signed, because NATO needed time to close remaining bases in the country.
U.S. President Barack Obama has said that the United States plans to leave around 9,800 troops in Afghanistan next year. NATO military planners are also looking to raise about 4,000 troops from other NATO and partner nations, but there is some reluctance to offer troops without the legal certainty.
(Additional reporting by Krista Mahr in Kabul and Missy Ryan in Washington Editing by Jeremy Gaunt)