Never in his decades of stardom has Tom Cruise been more delicately poised than he is right now.

Paramount is pulling together a fourth "Mission: Impossible." There's no question the studio intends to make another installment in the valuable franchise -- even if some industry pundits speculate that it might replace the 48-year-old actor in the Ethan Hunt role.

The studio is monitoring the overseas performance of Cruise's latest film, the 20th Century Fox domestic underachiever "Knight and Day," to see whether the star retains his longtime hold over foreign audiences.

A former studio chief suggested that Paramount might not face any downside in recasting the role in "M:I-4," at least not domestically. "'Mission: Impossible' is a brand," he said. "It didn't have anything to do with Tom Cruise in the beginning."

For its part, Paramount vice chairman Rob Moore said on Tuesday: "We absolutely are excited about having Tom Cruise star in this movie."

Meanwhile, Cruise is actively looking at other possible roles. He attended a table read this week at the Saddle Ranch eatery in West Hollywood for a Sony project to be produced by Will Smith's production company, Overbrook Entertainment. The film in question, "Paper Wings," is set in an urban-cowboy world, and Saddle Ranch had the right ambience for the read because it features a mechanical bull.

Chances are that before he mounts a bull, Cruise will reprise his role in "Mission: Impossible 4." But a disappointing start for "Knight and Day" has Hollywood wondering whether Cruise is still connecting with the American audience or whether the film's timing and marketing campaign were to blame for its lackluster grosses.

Such questions are the backdrop for Paramount's scrutiny of the foreign box office receipts overseas. "It all depends on whether Tom Cruise brings in foreign bucks," said one executive not associated with the project.

"Knight and Day," whose release was delayed in many countries until after the World Cup, will open in Australia, Brazil and Spain this weekend. The larger European markets and Japan are still ahead.

Paramount hopes to have a script for "M:I-4" pulled together within weeks so that production can begin by the end of the year and the film could be in theaters for the 2011 holidays.

But Paramount wants to set a budget "more consistent with a first movie than a sequel," per another source. The goal is to keep the cost at or below $140 million -- significantly less than the 2006 third installment's $165 million-plus. Obviously that means the studio is leaning heavily on Cruise to be flexible about his deal. Paramount is not offering any gross participation, and Cruise surely won't be expecting anything like the $20 million upfront fee that he commanded when business was better for him and for Hollywood.

But for Cruise at this moment with this film, money is not the central issue. "Everybody will do their best to make it work," said one of his representatives.

Alluding to the blowup when Sumner Redstone, the chairman of Paramount's Viacom Inc parent, publicly savaged Cruise after "M:I-3," the rep added, "No one wants a repeat of what happened last time."

At this point, Cruise's reps are determined to protect the star. Even before "Knight" turned in a disappointing domestic opening of slightly more than $20 million, a furious game of spin and counterspin was under way. In what clearly has been a strained relationship with the star's representatives, Fox marched out marketing chief Tony Sela to take the blame for the film's opening in an interview with the Los Angeles Times.

That has not quelled a furious attack from Team Cruise, which blames Fox generally and co-chairman Tom Rothman in particular for the film's soft domestic performance. The film has earned about $62 million to date, and should end up in the $75 million range.

"The correct story is, there's something wrong with Tom, but it's not Tom Cruise," insisted one of Cruise's representatives.

Team Cruise points out that the star pulled in better boxoffice for MGM's "Valkyrie," a film that should have been more challenging to market than a popcorn movie like "Knight and Day." The 2008 war drama finished with $83 million in North America.

Cruise's reps said Rothman engaged in micromanaging, leading to delays in responding to prerelease research indicating that the movie was not alluring to audiences. And they question a number of marketing decisions, including why the studio never updated a teaser poster that didn't show the faces of Cruise and his co-star, Cameron Diaz.

The Cruise forces said the release date also was a mistake. They believe the film should have opened in late July. As it was, "Knight" was moved away from a July 2 release date that would have put it opposite the "Twilight" sequel "Eclipse." The studio and the actor's reps were worried that Cruise's film would open far behind that behemoth and that Cruise (and Diaz) would be cast in unflattering contrast with the young vampires and werewolves. As it turned out, the film opened in third place, behind "Eclipse" and "Grown Ups."

A Fox source said though the studio has acknowledged issues with the ad campaign, other criticisms amount to "Monday-morning quarterbacking."