The war in Afghanistan is now 17 years old - making it the longest-running war in United States history. To put that number into perspective, young Americans can now enlist to fight in a war that began before they were even born.
The war in Afghanistan that was started under President Bush and continued under President Obama, is now in the hands of President Trump -- who's taken a drastically different approach than his predecessors. And making sense of Trump's war strategy has been on the minds of many.
Trump, who said his initial instinct was to pull out of Afghanistan, had a change of heart when sworn into office. And instead of reducing U.S. involvement, he increased it.
The Taliban resurgence now threatens large parts of Afghanistan, an ISIS-linked group has emerged, and civilian deaths are expected to rise this year, nearly two decades after the United States invaded the country following the September 11 attacks.
According to the UN, in 2017 more than 10,000 civilians were killed or injured as a result of the conflict — and it fears this year's number of war injuries in Afghanistan will be considerably higher.
Many people have lost their lives and millions have been forced to flee their homes, since the beginning of the war in Afghanistan. And the financial cost of this war is also upward of a trillion dollars, according to some estimates.
So why is there war in Afghanistan and why did the United States invade it in the first place? Watch to find out.