In happier times, yesterday’s opening of the more or less 2,600-foot tall Burj Khalifa, far and away the world’s tallest building, would have been an occasion for untrammeled pride and celebration, not only in Dubai itself but throughout the Gulf region.

Instead the emirate is struggling with a $100 billion debt mountain and its reputation with investors has been damaged by the badly handled restructuring of the $26 billion that state-owned Dubai World owes its creditors.

However for all the bad news that has come out of the emirate in recent months, yesterday’s official opening of Burj Khalifa by UAE Vice President and Prime Minister Sheikh Mohammed bin Rashid Al-Maktoum, who is also the ruler of Dubai, was a momentous occasion. The engineering achievement of this half-mile high structure is quite extraordinary. Designed to withstand earthquakes and winds, which, at the very top of the 200-story building, can reach over 90 miles an hour, the “superscraper” is a source of superlatives. This loftiest of structures — that stands tall at 828 meters — has taken almost six years to build. It is likely that it will be a long time before any other developer in any country seeks to outdo it.

Although the developer — Emaar Properties — is itself partly owned by the Dubai government, it has taken a heavy loss on its US real estate investments. Burj Dubai has already turned a profit for the company. Some 90 percent of the 1,044 prestigious Armani-designed apartments were sold before the crash. Commercial interest in the 49 floors of office space, totaling 300,000 sq. feet is reportedly still high and the world’s first Armani hotel remains on track to open this spring.

Therefore while an estimated $190 billion of new property investments in Dubai are currently on hold, this staggering key-note development has proven an outstanding success. Indeed it has been pointed out that two of Burj Khalifa’s predecessors as the tallest structures on earth — New York’s Empire State Building and Kuala Lumpur’s Petronas Towers — were both completed and opened in the teeth of a recession.

The authorities in Dubai may still have some serious questions to answer over the opaque and abrupt way Dubai World’s financial troubles have been managed but Burj Khalifa is a reminder of the vision, which has driven the quite remarkable real estate development in the emirate. Because the downturn will end and investor confidence will return, if not fully this year then probably during 2011, Dubai’s developers will resume their plans, albeit with perhaps greater caution and financial depth than heretofore. Indeed the emirate may even be able to overcome the memory of the Dubai World debacle and finesse its long-standing tradition as an entrepot hub and create the financial center which was part of its original vision.

So at a time of profound pessimism and sky-high debt around the world, the sky-high Burj Khalifa, as it is called now, is a mighty finger pointing upward, toward better and altogether more prosperous times.