In the past month no US troops have died in combat in Afghanistan. It's an extraordinary fact, because troops have died in combat every month in the last 5 years, according to CNN.
For comparison, around 237 American soldiers were killed in 2012, and 351 in 2011, according to the Pentagon - on average 20-30 deaths per month.
What's the secret behind the drop in casualties? The US military has made a strategic decision to do less of the fighting, and leave 80% of combat operations to the Afghan troops. As a result, the Afghan death toll is up, CNN reports. More than 3,400 Afghan soldiers and police were killed in 2012, almost twice as many as in 2011.
In addition there are simply fewer US troops on the ground, with the withdrawal of some 40% of US forces last year.
A further reason may be that Afghan insurgency has died down, which means civilian deaths are down too, according to the UN.