The recent spate of attacks by Afghan forces against their coalition counterparts is troubling, to say the least, but it should not change the timetable for withdrawal.

The announcement earlier this year by Defense Secretary Leon E. Panetta that the United States will end its combat mission there in 2013, one year earlier than expected, remains a viable plan.

The military calls the attacks on coalition members “green-on-blue” or “insider” attacks. The number of coalition troops, mostly American, killed by their presumed Afghan allies this year has topped 50.

It is a startling number that demanded a response by commanders on the ground. So now American and NATO service members always have a loaded magazine in their weapons and there is a program, “Guardian Angel,” that calls for one or two soldiers to monitor the Afghans during every mission or meeting. In addition, the Afghan government is doing more to monitor the off-duty movements of its soldiers and police.

Still, as the last of the 33,000 “surge” troops ordered by President Obama in 2009 leave Afghanistan, the question remains as to what will become of the country. The Taliban, toppled from power following the 2001 U.S. invasion, started regaining momentum when America turned its focus to Iraq.

Politically, Afghanistan has had parliamentary and presidential elections and improved women’s rights under President Hamid Karzai, but his government is riddled with corruption and has grown wary of cooperating fully with the United States. And there is concern over the opium trade, which has fueled the rise of the Taliban. Political instability has become the norm, and growing insider attacks only raise more questions on the timetable for an exit. Some analysts consider asking Afghanistan to assume full security responsibility in 2014 to be a lofty goal.

But the war in Afghanistan has stretched for 11 years. Staying beyond 2014 will only cost more American lives while doing little to ensure the country’s future.

A timetable was similarly set in Iraq, where the combat mission ended in August 2010 and the last combat forces left in December 2011. While the central government remains weak and the target of sectarian attacks, no widespread civil war has broken out.

The rise in insider attacks in Afghanistan is a disturbing trend that must be dealt with on the ground, but should not be used as an excuse to reverse American strategy there.