Nearly 90% of American cities with populations above 50,000 have SWAT teams, more than four times the level of the mid-1980s
As with so much else in American governance, the explanation starts with federal cash. Every year Congress passes the National Defense Authorization Act, which sets out the Defense Department's budget and expenditures. The version passed in 1990, in the wake of a sharp rise in drug-related violence, allowed the Defense Department to transfer military gear and weapons to local police departments if they were deemed "suitable for use in counter-drug activities". Between 2002 and 2011 the Department of Homeland Security, established after the attacks of September 11th 2001, disbursed more than $35 billion in grants to state and local police forces. In addition the "1033 program" allows the Defense Department to distribute surplus equipment to local police departments for use in counter-terrorism and counter-drug activities. The American Civil Liberties Union found that the value of military equipment used by American police departments has risen from $1 million in 1990 to nearly $450 million in 2013.