Even if you think that making (certain) drugs illegal is a good
idea, naming this the "War on Drugs", or calling for a "War on
Drugs" above and beyond simply illegality, is a bad idea.
This is because war is something that (generally) you win or
loose. But it's impossible to a War on Drugs; it's impossible for
the government to eliminate any sort of undesirable behavior,
from jay-walking to murder. And if a War on Drugs makes sense in
spite of this, wouldn't it also make sense to declare a "War on
Crime"?
So, what's the problem with an illogical name/slogan? The problem
is that it influences the way that people look at the problem.
Rather than looking at drug use as something to be minimized and
contained, like law enforcement does for other crimes, it looks at
it as a problem that must be eliminated, something that must be
won. Since whatever current efforts are being made don't
work, why, pour more resources into it. And if that doesn't work,
pour even more resources into it.
Also, war is a (hopefully) unusual state of affairs, somewhat like
a drawn out emergency. The rules are different in a war: people
get drafted, martial law can be imposed, foreign civilians are
killed by collateral damage... With the idea that the fight
against drugs is a war, some people are more willing to put up
with negative things, like insanely harsh sentences for drug
crimes and the loosening of requirements for search and seizure.
In fact (this is from memory), Daryl Gates (or some other police
chief) once claimed that drug users should be shot, because if
there's a War on Drugs, then taking drugs is an act of treason.
So if you want to keep drugs illegal, come up with some other
phrase for it.