Sitting at a sidewalk tea stall in Phnom Penh with an iced coffee, I was flicking through the latest stats from the State Secretariat of Civil Aviation: in the first eight months of this year, total international passenger traffic through our airports hit just over four million. That is a drop of nearly 10 percent compared to the same period last year. Out on the street, the moto drivers are still complaining that the tourists aren't showing up the way people expected. Seeing fewer unfamiliar faces hauling big bags through customs definitely matches the feeling that things are a bit quieter than this time last year.

Yet, curiously, while passenger numbers slipped, the cargo planes in the sky have been keeping busy. Local media report that air freight volume didn't drop at all over the same period—in fact, it climbed 17 percent. Exactly what is packed inside all those boxes moving in and out is anyone's guess, as the tea stall owner noted, but out at the airport, the daily roar of arriving and departing flights sounds much like it always has, with hardly any noticeable dip in traffic.

As one official pointed out, the whole sector is in a delicate spot right now, with passenger and cargo traffic heading in completely different directions. Even so, the planes are still flying and the trade routes are turning. Sitting there at the tea stall listening to a jet roar overhead, you just hope business here starts climbing step by step, just like the air cargo numbers.