An increased presence of U.S. troops in Afghanistan will likely serve as a "magnet" for insurgent activity against U.S. and Canadian soldiers, experts agree, but will also help stem insurgent activity over the long term and pave the way for reconstruction projects.

U.S. President Barack Obama has announced his intention to draw down his country's involvement in Iraq, while sending an additional 17,000 troops to Afghanistan in the coming months.

Reinforcements are welcome given that insurgent activity rises in the warmer spring months, experts agree.

But it is likely that an increased U.S. troop presence will lead to short-term problems before it can produce long-term benefits that could allow the Canadian mission in Afghanistan to end in 2011 on a positive note. The issues include:

More casualties

A boost in U.S. troop levels will likely lead to a short-term spike in Canadian soldier injuries and casualties, experts say.

Canadian troops in the volatile south need reinforcements as they battle an ongoing Taliban insurgency. They have suffered a particularly deadly winter, as 14 soldiers have been killed since December, including three this week in the normally calm Arghandab district.

But an increase in military activity throughout the country will leave troops more vulnerable to insurgent attacks.

And that insurgency will likely get a boost from Pakistan, where three extremist groups have decided to set aside their rivalry and renew the fight against international troops stationed in Afghanistan, reports say.

"So an additional 17,000 forces in (Afghanistan) merely serves to act as a magnet for the combined (international) force and therefore I think the Canadian forces - in a strategically crucial part of the country - can expect an increased tempo in operations against them," Paul Burton, policy director with the International Council on Security and Development, told CTV.ca in a telephone interview.

According to Burton, coalition forces can hope that an increased American presence in Afghanistan will test the resolve of militant groups.

"We know that they're there for the long term, that they're not a fickle foe, and a lot of these guys are fighting purely to drive western forces out of the country," Burton said.

Long-term security

It is likely that a surge in violence will be followed by a weaker insurgency as U.S. and Canadian troops secure and hold more territory once controlled by the Taliban.

As it stands now, says one international security expert, there are not enough Canadian troops on the ground to hold the land they have cleared of militant activity.

But the Americans will bring with them what are known as "force multipliers," such as helicopters and other vehicles, "which allows you to get more out of X number of infantry that you have by using them more effectively, moving them around more easily and so forth," Stephen M. Saideman, Canada Research Chair in International Security and Ethnic Conflict at McGill University, told CTV.ca.

With greater mobility may come greater risk of an attack by insurgents, but it will also allow soldiers to root out Taliban activity and lessen the number of attacks as time goes on.

While the exact impact American troops will have is unclear, one retired Canadian colonel is certain that it will reduce insurgent activity and reduce the threat to Canadian troops.

"(U.S. troops) will make a significant difference by being able to dominate the terrain, impose our will and interdict the Taliban's passage," retired Col. Michel Drapeau told CTV Newsnet on Wednesday.

Legitimacy for central government

Since the central government under Hamid Karzai was established in 2002, its influence has not reached beyond the capital, Kabul, to outlying areas.

Local government essentially consists of village elders, but stability in the country depends on a strong central government that Afghans can trust in, which will lessen the likelihood they fall under the influence of local Taliban leaders.

"So if the international community can work with better governors and if Karzai or his replacement can make decisions that lead to people looking to the government as being a little bit more legitimate and less corrupt, then you're more likely to see better things happening on the ground," Saideman said.

According to Burton, Canadian and American troops can work together to boost the central government's legitimacy by developing reconstruction and infrastructure projects that local communities need, while making it clear they are working on behalf of leaders in Kabul.

"All the international community can do there is try and attempt to forge that link and manage it as carefully as possible," Burton said.

Winning the PR war

In the end, a boost to U.S. troop levels will mean little if it doesn't help produce an increase in intelligence tips from Afghans on insurgent activity in their communities.

But it is not the number of militants that soldiers can round up from the intelligence that is important, Saideman said.

The true measure of success will be whether soldiers receive more help from Afghans as they try to choke off the insurgency for good.

"The act of them telling us what's going on is that, by themselves, they're indicating that they're betting on us rather than betting on the Taliban," Saideman said. "And that really is where the rubber meets the road."