It isn't an ideological war, at least not in the political sense.
It is more an example of Warlords carving apart a State.
Here's an overview from the BBC as a simple refresher course on how bad it is... and how hard it is for the Government of Mexico to make any rapid progress against the Cartels.
But perhaps such a broad brush image is simply overwhelming to try and take in...
Very well, let's take today's news reports just to make a couple of examples of the danger:
Here's a very local, rural case highlighting how it is nearly impossible to keep police on the job in places where the Cartels can casually overrun the region and annihilate any trace of State authority.
At the other end of the spectrum, here is a report of how trivial it is for the Cartels to operate across Mexico's borders. This is not only an example of their danger to the Mexican authorities, but it is also a signature example of the danger faced by other countries that have the misfortune to border Mexico or be along the smuggling routes that lead through Mexico.
This is going to have to be brought to an end. The ongoing effort to fund the Government of Mexico's fight (the Mérida Initiative) isn't the way, either. Its implementation schedule alone has been far too slow to offer much to Mexico other than the hope of losing less often. There are also serious institutional problems in Mexican courts and law enforcement (and parts of the military, just on a lesser scale) preventing more normal means of addressing the threat that no amount of outside financial aid will solve.
If (and this is a *big* if) Mexican pride can be set aside long enough for a regional intervention to be formulated and implemented ...a Plan with real victory over the Cartels as the objective... there is some hope of the State reasserting itself. Weapons, trainers, information, secure salaries for officers and men of State authorities, and in contested areas adjacent to other countries the means and manpower necessary to secure and hold those zones are all going to be needed. Some of those means and manpower wouldn't be Mexican, either.
If not, then matters will certainly bring things to an end all by themselves. The State will simply fail. After that, there will still be an intervention. There simply has to be one. Failed State Mexico would be too dangerous for any of its neighbors to tolerate. The only doubt would be as to whether such an intervention would lead to success where the Government had failed, or just an open sore of bloody stalemate.
Mexico and its neighbors can own up to the enormity of the problem and get on with paying the costs of a real, full-scale "Plan", or
...they can pay far more in blood and treasure later.
Note: I'm not even going to address the 'War on Drugs' arguments as to why Americans should take some specific action (militarize the border; decriminalize the traffic; whatever). In my opinion the matter of the Cartels has long transcended any one criminal activity and is now better described as Warlords carving apart territory. This is more like the collapse of Somalia over the last 30 years, or if you prefer the historical example the disintegration of much of China by the 1920's into dozens of 'bandit kingdoms' and Warlord-holdings. Mexico isn't there yet, by far, but that's the path they are on.
Wikipedia linked for convenience only. Please consult citations there for original research.