The Taliban -- the most influential terrorist group in Afghanistan -- have denied any involvement in the attack, which has turned the spotlight back on the country's 16-year war. Like the ISIS attack on an ice cream shop in Baghdad earlier this week, this sends an utterly uncompromising message that nothing is off limits. There are currently more than 8,000 US troops in Afghanistan, along with 6,000 from NATO and allied countries. US forces recently have increased their targeting of ISIS, focusing on potential international terror threats inside Afghanistan, as well as the local fight. At the peak of the US troop surge in 2009 and 2010, there were about 130,000 coalition troops inside Afghanistan.

Source: CNN May 31, 2017 11:15 UTC