THE UTAH JAZZ began the defense of their Western Conference championship Friday with a plan to do what any conquering army does after a successful campaign - start another one. Once you've won some battles and overrun some countries, it's a hard habit to break.

Actually, the opening of the Jazz's training camp this year has something to do with returning to the NBA Finals, something to do with business, and something to do with laying siege to Idaho's largest city. After years of holding camps in St. George, Salt Lake and Cedar City, they moved their preseason command center to western Idaho with intent to claim the area as part of the Commonwealth of Utah.That the Jazz would be here in foreign territory, after their best season, was first and foremost a simple business decision. Team owner Larry H. Miller, a full-time basketball fan and part-time auto tycoon, bought up a large share of the car dealerships in the Treasure Valley within the past year. His signature slogan "Whatever it takes!"

will now ring all up and down the Boise River.

And because he was feeling so good about things, Miller decided the best way to celebrate would be to bring 17 of his closest friends along - in other words, all the players invited to camp. Karl Malone was way ahead of him, having his Harley-Davidson shipped up to help him get through the down times. But the rest of the players will probably spend most of their time trying to decide if they want to see the Idaho Botanical Gardens or just stay in their rooms.

Although Boise is a six-hour drive away from Salt Lake City, the Jazz have been eyeing Idaho's capital city for several years, trying to decide whether to annex it as part of the Jazz empire. It remains an intriguing city to conquer.

Traditionally, Boise has been the domain of the Portland Trail Blazers - a team that held its training camp in the City of Trees numerous times. They have commanded most of the NBA loyalty in the city. Seattle, too, has a significant number of fans here.

However, that was before the Jazz started making their move. They played preseason games here in 1984 and 1987, not surprisingly against the Blazers. Next, they went to the Western Conference Finals three times in five years, thus drawing increasing attention to themselves. Last year they went to the NBA Finals, outstripping the Blazers in both success and publicity. While the Blazers were busy trying to figure out how to handle such troublesome stars as Rasheed Wallace and Isaiah Rider, the Jazz were working on their citizenship merit badges.

Then Miller bought up most of the cars in Idaho and started plotting his takeover.

"This is a place we consider Jazz territory," said Jazz vice president for public relations, Dave Allred.

In the 1820s - just after Robert Parish signed his first contract - the North West Fur Trading Company began setting up shop in the area. Legend has it that upon seeing the tree-lined river from what is now Bonneville Point, French fur traders exclaimed, "Les Boise! Les Boise!" which interpreted means "Let's put a Larry H. Miller car dealership here!"

But the dealership, and the Jazz, were a long time arriving. First, the city grew to a metropolitan population of more than 300,000. In the process it became a city most NBA teams would like to be aligned with. It has its own university, art museum, choir, philharmonic orchestra, ballet company, opera company and - the ultimate sign of civilization - a string of Starbucks coffee houses. As it grew, it acquired thousands of displaced Californians, who moved up to take advantage of the cheap real estate and blue skies.

Consequently, the Jazz have been keeping their eyes on Boise for some time, lurking in the background, hoping to become the city's adopted team. They arrived Thursday night under cover of darkness to implement the plan, and the first shot in the battle over Boise was fired. The Jazz were staking claim to the biggest city in Idaho. And from now on, anyone living in Boise can assume that when Miller utters his slogan "Whatever it takes!," he isn't just talking about selling cars; he's talking about expanding the empire.