Well, with the death of Moammar Gadhafi, only two of the dictators that Frank Drebin fought in the opening scene of the 1988 movieare left (Mikhail Gorbachev who was ousted from power in 1991, and Fidel Castro, who though still kicking, is in semi-retirement these days).
Anyway, if the movie were made today, who would be in this rogue gallery of corrupt leaders? Kim Jong-Il would be an obvious choice, as would Mahmoud Ahmadinejad. And you can probably throw Hugo Chavez in there for good measure.
Who else?
And you may remember how Frank wiped the birthmark off Gorbachev’s head and punched the Ayatollah’s turban off to reveal a mohawk. What kind of gags would you put in for when Frank starts fighting this new cast of dictators?
Kim Jung Il is the only one to immediately spring to mind.
Since he wears a gray coat and pants frequently, maybe Drebin could punch Kim so he falls back into a mop and bucket and ends up looking like a janitor. Kim could then attack Drebin with the mop, allowing the Police Squad hero to spin him around by it.
i’d rather he take out over-rated pop, rock and R&B artists. being anti-american doesn’t automatically make you bad. 
It would be pretty tough to come up with a half-decent. Ahmadenijad and Chavez don’t work very well —the former isn’t his country’s leader (and who’s heard of Khamenei?), while the latter is his country’s legitimately elected leader. Kim Jong-Il would be a solid choice. So would Mugabe, of course. Maybe throw in Assad (Syria) and al-Bashir (Sudan) — but neither of them are well-known to the general public, so they aren’t great. Putin isn’t enough of an enemy, nor is Hu Jintao. Even if we turn to non-state leaders, bin Laden and Escobar are both dead (the latter since before the original set of Naked Guns ended). In short, pretty tough.
Putin’s macho would be a good gag. No matter what Drebin does, Putin somehow ends up shirtless, flexing his muscles.
No answer to the OP, but as an aside, I remember seeing a revival of Billy Wilder’s The Apartment (1960, black & white, Shirley MacLaine/Jack Lemmon) a couple of years ago and in one of the scenes they’re talking in a bar and she says something along the lines of “So what do you think of this Fidel Castro?” That was really surreal.