The World War II battleship USS Missouri, to be recommissioned Saturday in San Francisco, is already at war. The enemy is Missouri Gov. John Ashcroft, and the booty is a $250,000 silver service in the governor's mansion.

Since the Missouri's 16-inch guns cannot reach Jefferson City, the Navy is considering suing the battleship's namesake state, Defense Department officials said. Navy Secretary John F. Lehman Jr. is "dumbfounded" by Ashcroft's refusal to return the treasure that once graced the captain's table aboard ship, the officials added.

For his part, Ashcroft is disappointed that the Navy would consider "creating ill will" among the people of Missouri, "who look with pride upon that ship and have for decades," spokesman Randy Sissel said yesterday. The governor is looking forward to the recommissioning ceremony Saturday but plans to leave the silver behind when he travels to California, Sissel said.

As to the Navy's claim of ownership, Republican Ashcroft believes that the issue "ought to transcend legal arguments," Sissel added.

At stake are a silver punch bowl engraved with the Missouri seal and 321 goblets, plates and other pieces that the people of Missouri donated to the original battleship Missouri in 1904, at a cost of $3,000. The service saw duty on the second battleship Missouri during World War II and was aboard ship when the Missouri steamed into Tokyo Bay in 1945 to accept the Japanese surrender.

But when that ship was decommissioned in 1955, the silver was shipped back to Missouri -- "on loan," a Navy official said pointed- ly.

Now, as part of Lehman's plan to reactivate four behemoth battleships, the Missouri is returning to Pacific Ocean duty. For more than a year, the Navy has been writing and telephoning, and finally it has dispatched Capt. Albert L. Kaiss, who will command the Missouri, to Jefferson City to wrest the silver from its caretaker.

Navy officials said Missouri natives aboard the battleship are disgusted by their governor's behavior. But Sissel contends that the service was donated by the people of Missouri for the first battleship, which was decommissioned in 1919, not for the 58,000-ton vessel being returned to service now.

The original ship "no longer exists," Sissel said. "In the governor's view, it's basically a historical artifact now."

The service is on display in the governor's mansion, which anyone may visit free of charge on certain days, the spokesman pointed out, and is rarely used for entertaining. For Missourians with a "special feeling" for the ship and for visitors to the state, he said, the silver is a source of pride that should not be sent back to sea.

"It's sort of like, do you take all the Monets in the world and lock them up in one museum, and say only a select few can view them?" Sissel said. He said some silver purchased for the second USS Missouri will be returned to the refurbished ship.

Navy officials, on the other hand, said they need the 1904 silver service so the recommissioned battleship can entertain foreign leaders in proper style. A battleship captain cannot invite an ambassador to tea and use "five-and-dime flatware," one officer said.

A showdown may come Saturday, when Lehman, Ashcroft and Defense Secretary Caspar W. Weinberger gather in Weinberger's hometown for the ceremony.

"The big question is whether Ashcroft will come bearing silver," one Navy official said darkly. "It appears that he will not."