Population growth generally slows as resources become less abundant and competition increases with other species. There really isn't any danger of wolves taking over the country like a plague.
That might be true of wolves - but what of wolf hybrids, bred from the mating of the wolf and a dog or coyote? While similar, this is how new sub-breeds develop, and there is no telling how such a sub-breed's characteristic will play out in the ecosystem. Unlike the wolf, the modern dog has had thousands of years to become familiar with humans and our characteristics; yes, in many ways, they've become dumber and weaker (such as the hair-count-per-follicle reduction) than wolves, but they very well could be developing characteristics which make them more of a nuisance, per-wolf, to human existence. And changing food sources (deer to things like pigs) can also change behavioral patterns, I imagine.
Yes, I think the problem is largely due to an excessive number of deer and other ungulates. Trophy hunters probably don't know what I'm talking about when I say this due to a sparsity of large bucks in many places, but it's true; there's just entirely too many does out there. The doe populations are essentially going unchecked to the point where there aren't enough bucks to fertilize all the willing and ready females, and so the females go into heat late in the season. The result? You guessed it: plenty of young, vulnerable, and unfit-to-get-through-winter fawns which make wonderful snacks for a pack of wolves. This all culminates in a surging predatory population.
Combine this with farmers and ranchers having to constantly deal with deer eating a substantial amount of their crops/feed. Out here, deer are called prairie rats for a good reason: short of killing them, there's no keeping them out. Add to the fact that, in many places - in and near TOWN - the deer have grazed grass down to the mud (thankfully, this was a wet year, but I can't even begin to imagine what it'll be like next year if it gets dry again).
And it's not just wolves making a lightening-fast resurgence, either. This past summer (since May) there have been two mountain lion sightings within 200 yards of my house, one killed a deer about 150 yards from the front door, and there was a territory fight between two very loud and angry cougars about 100 yards from my house one night (I found tracks and plenty of disturbed foliage.) Several cougars have ventured into town during daylight hours. (This is RC, SD - population 80-100k or so, a fair way from the Rockies and about 150 miles from the Missouri).
And then you've got all the mountain lion sightings as far east as NY.
Not to forget the wolves they've found in Central Park, NYFC.
We need to open up both trapping and hunting for wolves and coyotes, to a significant degree, within a couple of years. I'd say trapping before hunting (as its more passive and, I think, less likely to have a significant hindrance on a population but to stop its expansion.) I'd say wolves sooner than coyotes, certainly, due to their explosive population and increased numbers.
(By the way, canines are not carnivores, strictly speaking. They are omnivores, like we and dogs are, though their diets are primarily meat due to both preference and (like us) biological necessity. IE, they're not going to graze, but they need the nutrients and fiber from plants and roots, too.)
... but hey, what do I know. This is just what I think; the guys and gals in the various land and park management systems likely know more about it, more definitively, and they're skilled in the matters at hand.
Or maybe they're just scared skittleless of being the ones responsible of another die-off, aka Yellowstone not that long ago... Oh, wait... what was it that precipitated the die-off there, again? Ungulates overgrazing, or something like that, you say? *grumble*
