Your story is misleading, and yet this is the #1 Google search for drug arrests more than 3 years later. I’m against the War on Drugs, too.
On the link you provide in the first paragraph, it says there were “1,646,212 were for property crimes” which would be higher than “1,552,432 arrests” for drug abuse violations. However, it does appear that “property crimes” are a mix of crimes like larceny-theft and motor vehicle theft, and the FBI does mention “The highest number of arrests were for drug abuse violations.” The Bureau of Justice does as well.
You don’t mention that there’s 30 categories of crime.
You don’t mention that drug arrests only make up 12.7% of overall arrests, although the math is easy to do with your numbers. That would indicate that nearly 90% of law enforcement efforts are not spent in pursuit of drugs. (No question, though, arrests have increased as the Department of Justice says, “In 1987 drug arrests were 7.4% of the total of all arrests reported to the FBI; by 2007, drug arrests had risen to 13.0% of all arrests.”)
You don’t mention how extremely rare it is to get prison time for possession. “Drug abuse violations,” according to the FBI, includes every category of drug-related arrests, from possession to distribution. It is drug dealing not drug use that puts people in prison. Violent crime makes up nearly 50% of the prison population, and drug-related crimes 21%. Of those in prison for drug convictions, less than 1% are of those are for simple possession of marijuana, according to PolitiFact. 99.9% of those sentenced to federal prison for any drug-related crime were sent to prison for something more serious than simple possession, according to data in a 2012 Department of Justice report.