How to eliminate terrorism, guerillas, drug cartels, tax evasion, money laundering, violence, mafia, enemies of the USA and how to improve our economy..... Considering that: a) All of the above activities are done using huge amounts of cash leaving no trace ... b) Drug lords in Colombia have billions stashed in the so called "Caletas" which are underground climate controlled rooms full of US dollars... c) Violence and drug trafficking in Mexico is similar to Colombia ... d) About 80% of the drug produced in the world is bound to the USA and governed by cash... e) Tax evaders stash huge amount of cash ... f) The FARC guerilla in Colombia operates in a cash basis ... g) Money laundering is a cash operation ... h) Enemies like Ahmadinejad ,Chavez, Chapo Guzman, Fidel Castro, etc finance their bad deeds in cash ... i) Crime families like the Gambino family and others also are cashed based ... j) Hit men are paid in cash as well ... k) Islamic terrorism like Al-Qaida is cash based ... I propose that the USA start printing dollars of a color other than green, let's say red. The USA would give certain number of weeks or months for those people or institutions that have green dollars to exchange them for the red ones. Obviously you will have to explain or justify where your huge amounts of money come from. For example you have to explain to the USA government where your $60000000 of green dollars comes from. May be they came from drug trafficking, money laundering, terrorism ...