THEY SMILE IN YOUR FACE, all the time, they wanna preempt your rotten, struggling shows … the affiliates. Or something like that.

ABC brass will meet with their stations in Los Angeles beginning today, representing the last of the four spring affiliate conventions. These are the annual rituals where network officials get together with station exex, proudly parade their new shows for the coming season and either A) bask in the glory of or B) sheepishly take lumps for their May sweeps performance.

Those network-affiliate relationships remain increasingly under siege, though thus far you couldn’t tell based on reports from the meetings. Even NBC, which slogged through its worst season since Brandon Tartikoff was first introduced to Mr. T, seemed to mollify its stations with a May sweeps win and what’s perceived as a strong crop of new series.

Still, all is not well in the affiliate henhouse, with studio wolves leering at those plump, sated stations and their delicious prime time clearances. In this case, the windows of opportunity are created by the networks laying eggs, in the form of low-rated series.

Over the last year, several factors have converged to place additional stress on the network-affiliate bond. First off, the networks, suffering through a sluggish economy and advertising slump, sought to cut compensation to stations, at a time when affils are dealing with their own financial woes. Loyalty has its merits, but money tends to speak loudest when it comes to prompting stations to clear network shows.

At the same time, the government has been tinkering with the financial interest and syndication rules, making it easier for the networks to produce and own the shows they air.

Seeing a future in which the networks supply more and more in-house product, and noting the growth of Fox Broadcasting Co. and Paramount’s success with a first-run hour like “Star Trek: The Next Generation,” the other studios are throwing more of their resources into first-run syndication, creating ad-hoc networks that don’t rely on the Big Three webs.

This is partly a defensive measure, partially sheer economics. At a time when CBS is cutting back on the length of initial orders for new series, a syndicator can start with an out-of-the-gate 22- or 26-episode order on a new program, helping amortize the cost of mounting a series.

A final development involves the networks’ increased reliance on other businesses, such as cable, to create second fronts, as it were, and offset lost revenue associated with shrinking broadcast shares. Stations tend to get nervous about things like that, and Fox’s establishment of a basic cable service, ABC’s creation of ESPN2, and NBC experiments like the Olympic Triplecast and CNBC (on-air spots for the cable service have been prominent during the NBA playoffs) will only fuel broadcaster paranoia.

THE NETWORKS HAVE ALREADY FOUND themselves feeling the pinch outside prime time. Last year, ABC pleaded with stations to air “Nightline” in pattern at 11: 30 p.m., while both ABC and NBC were forced by low clearance levels to return weekday time to affiliates. Syndicators gleefully moved to fill that void.

In late night, meanwhile, the preemption threat looms over all the new network series, with a lengthy roster of first-run and off-network properties waiting in the wings. Even CBS, after its deal with David Letterman, has had to struggle securing time periods for the host.

So far, major preemptions haven’t assaulted prime time except in the summer, where it’s become almost routine for several network shows to be cleared below Fox levels, down in the low-90 or even 80 percentiles, during any given week. Every time there’s a Billy Graham special in July or August, CBS suddenly finds itself looking up at the national reach of shows like “Rush Limbaugh” and “Baywatch.”

Networks, of course, can’t secure established hits without affiliate support, while stations go through the process of being wooed by syndicators, who show up with the wartime equivalent of chocolate and pantyhose. The mating ritual goes on, with the shape of broadcasting hanging in the balance.

THUS FAR, NETWORKS have relied on the old standbys to try and keep their alliances alive. Accentuate the positive. Strut out the stars, providing some Baton Rouge station manager the chance to get his picture taken with Jane Seymour. Talk about the importance of teamwork and partnership, and all the other stuff that doesn’t mean a heckuva lot when the bombs start dropping or the bill comes due.

Any way you try and slice it, television isn’t a simple equation any more. While the alarmism of a few years ago has subsided, many of the warnings that have been raised — like networks being forced to give back hours because of low clearances, or the existence of five or six “networks,” all shaving off pieces of a dangerously dwindling pie — remain possible, if not likely.

Already, Time Warner’s “Prime Time Entertainment Network” and Paramount’s action hours combine for five hours of programming a week, with two more from Time Warner on the way, as well as a weekly MCA first-run movie and a new hour from Columbia. Add it all up, and you’re two-thirds of the way to another Fox Broadcasting, if only a patchwork version.

Chicken Little may not have been entirely right, but he was on the right track: The sky isn’t falling all at once; rather, the television of the past — based on networks and affiliates combining to create strong, unified broadcast entities — may just end up sliding, gradually, into the sunset.