Any operation this significant re a foreign government’s criminal actions against the U.S. would take years to plan, organize, put together the staff/agents needs, and then operational surveillance time before they could begin to get arrest warrants, subpoenas, extradition notices etc. up and running.
I would say that this operation might have been started early in the Trump administration (perhaps by the DEA, aided by the CIA, FBI, US Border Patrol/Customs, ATF, and Organized Crime Task Forces across the U.S.) It might have been organized/started by the old Obama DOJ/Task Forces under Comey, the CIA under Brennan, and DOJ under Holder (doubtful) Lynch, etc.
However, I suspect that the bulk of the field work was done under Trump’s people and Barr has made a decision that it is time to start hauling in the suspects and closing down Venezuelan/Cuban/Nicaraguan drug operations.
If Barr has any intention of arresting people over 50 he’d better get to it.
Probably part of Project Python
don’t forget China in that list