Washington: This year’s Paris Air Show, the year’s largest gathering of the defense and aerospace businesses, will focus on unmanned systems such as the now-famous Predator since that is one of the few growth areas for the defense sector.

The show itself, which starts Monday, promises to be, simply, huge. Some statistics: more than 2,100 international exhibitors;28 international pavilions; 140 aircraft on display including the solar aircraft Solar Impulse; and 138,000 trade visitors plus 200,000 ordinary folks over the seven-day show.

But underlying much of the show will be a deep unease about the future course of American defense spending. Since the United States accounts for the great majority of the world’s defense spending, the serious prospect of cuts totaling more than $400 billion over the next decade — excepting the the costs of Afghanistan and Iraq — casts a pall over the show. The clouds began to gather at last year’s Farnborough Air Show when Lockheed Martin announced it would substantially reduce its presence at the show.

This year Lockheed took the same basic approach, with CEO Bob Stevens telling the press at their now annual pre-Paris breakfast that he would not attend the show again and his company would cut its spending on the show by one-third. That amounts to only a few million dollars but Lockheed, Boeing and Northrop Grumman are all wary of spending much money on such a high-profile event. The senior leaders at the Pentagon have made clear they are watching the defense companies closely and want them to keep costs under tight control.

On the other hand. Raytheon is playing up its attendance and offerings at the show, clearly more confident that their business model will benefit. Raytheon is doing well with international sales, which make up about 25 percent of recent sales.

While we have only Pentagon source on this, we have heard some grumbling about the costs and arrangements for Deputy Defense Secretary Bill Lynn’s entourage. Of course, whenever a senior defense official travels, there are comfortable hotels to book, rooms to get for security and communications folks. And, of course, international travel of any kind for people over 21 is rarely cheap. Given Defense Secretary Robert Gates recent criticisms of our NATO allies and their reluctance to expend blood and treasure in Afghanistan and other conflicts, Lynn will probably have a great deal to discuss. And he will have to address cost concerns among the partner countries planning to buy F-35 Joint Strike Fighters. Lynn will have help. The deputy of the F-35 program, Air Force Maj. Gen. C. D. Moore will attend the show.

For a glimpse at what will be on display among the unmanned aircraft, look no further than the Israeli chalet at Le Bourget. In a press release, the Israelis says they “will highlight unmanned systems technologies” from companies such as Urban Aeronautics, Elbit Systems. Aeronautics, BlueBird and IAI. Unmanned Systems Technologies Aeronautics Defense Systems will take the wraps off its new mini-UAV at the airshow. Bluebird Aerosystems will display several mini UAVs, including the MicroB, which is designed for covert missions.

Breaking Defense, which went live today, will be covering the show from beginning to end, in print and in video. The show begins next Monday and ends on Friday, except for the two days at the end of the week when the public can attend.