In another instance of an insider attack in Afghanistan’s ever-struggling security forces, a group of four Afghan policemen went rogue on Sunday night, attacking and killing the other nine police at a checkpoint in Uruzgan Province before stealing all the weapons and leaving to join the Taliban.

The Taliban has yet to claim responsibility for the attacks, and Afghan security forces are scrambling to try to catch the attackers before they defect to the Taliban with all of those weapons. It is rare, however, for them to manage to catch such attackers.

Insider attacks have been a huge problem in Afghanistan for years, starting with “green-on-blue” attacks by disgruntled Afghan security forces against US and other NATO troops, a problem that eventually led to the US and NATO avoiding direct contact with Afghan forces at all costs.

After NATO’s shift away from Afghan bases, the attacks still happened but were “green-on-green” attacks against other Afghan security forces. The recent trend has seen such attacks hitting smaller sites, where they have a reasonable chance of knocking it out entirely and making off with whatever gear remains.

Fueling this is not only the poor condition under which Afghan forces have to operate, but the shaky attempts to screen out potential attackers, which have allowed the Taliban in many cases to not just rely on would-be defectors but to plant their own existing fighters in these posts.