The Vietnam War ended in 1975. But it's still harming the health of Vietnamese people born after the conflict ended.
A land dispute has left a potential peace park at the site in doubt. Here's why a memorial that explains what happened the day of the attacks is important.
By inciting religious hatred, the recent attacks in Sri Lanka appear to have more in common with Al-Qaeda than past ethno-religious violence, which has sought specific political change.
Mass murders like the killings at a Pittsburgh synagogue are seen as the work of disturbed individuals. But America has allowed violence to become unexceptional, ignoring its root cause.
Though more consequences are likely to develop in the post-9/11 era, the war on terror, heightened government surveillance and Islamophobia are notable legacies of this early 21st century tragedy.
Scientists studying the atmosphere found help in an unlikely place – the aerial bombing campaigns of World War Two.
With the Taliban ramping up its attacks once again, the war in Afghanistan shows no sign of ending.