By Yaroslav Trofimov —wsj.com DUBAI—If you want to see what a tangle of geopolitical conflicts the Middle East has become, just look at its convoluted air routes. The Qatar Airways flight from Doha to Khartoum, Sudan travels in a semicircle and takes 5½ hours. A year ago it took two hours less and flew straight across Saudi Arabia—but that was before the Saudis cut off relations with Qatar. If you’re flying to Mumbai from Tel Aviv on Israeli carrier El Al, it will take you eight hours as the plane doglegs past Saudi Arabia and Yemen. A direct path would take around five hours. That detour is the result of the longest and most intractable Mideast conflict—between Israel and the Palestinians.

Airspace over many Arab and Muslim nations remains closed to El Al; at the same time, the region’s giant carriers such as Emirates Airline, Etihad Airways and Qatar Airways can’t fly over Israel as they head west to European destinations and beyond. As the seven-year Syrian war drags on, that nation’s airspace remains out-of-bounds for most international airlines, with the notable exception of Lebanon’s plucky national carrier, Middle East Airlines. Add to this war-related disruptions of flights over Iraq and Yemen and the latest conflict, between Qatar and Saudi-led Gulf states, in which Qatar Airways was barred from airspace over United Arab Emirates, Bahrain and Egypt as well as Saudi Arabia. “Few regions of the world are as fractious and riven by airspace wars as the Middle East,” said Oliver Lamb, managing director of the Ailevon Pacific Aviation Consulting. Airspace closures exact significant costs on the region’s economies (and airlines) as travel takes longer and becomes more expensive due to higher fuel costs.

For example, the popular Emirates flights from Dubai to Beirut usually take a J-shaped path as they head west to Egypt, veer sharply right over the Sinai Peninsula and then right again once past Israel. This means at least an hour more than the direct route Emirates used to fly over Syria before the war there began. The environment of shrinking access to airspace explains why an inaugural Air India flight from New Delhi to Tel Aviv last week was such a big deal. The new link transits Saudi Arabia and Oman, making it, according to Israel’s Prime Minister Benjamin Netanyahu, a huge “breakthrough” with geopolitical implications. It was the first time that Saudi Arabia allowed an Israel-bound commercial flight through its airspace, a testament both to the tacit rapprochement between the two countries and to the growing regional influence of India. “This development has much greater importance than most people note,” said Dore Gold, the president of the Jerusalem Center for Public Affairs and until 2016 the director-general of Israel’s foreign ministry. A number of other Asian air carriers are interested in following suit now that fuel-efficient flight connections to Israel can be established, he added. “Israel’s trade with the Far East has expanded enormously, and to sustain it you need enough air routes.” So far, this airspace detente only concerns third-country airlines, with Israeli and Saudi carriers barred from each other’s air. Such discrimination has already led to protests from El Al, which fears it won’t be able to compete if its lucrative Asian routes are challenged by carriers that offer cheaper and, crucially, much shorter flights.

Irrational airspace routes aren’t unique to the Middle East, of course. China is notorious for restrictions that close much of the country’s air to commercial air traffic. And, until 2008, flights between mainland China and Taiwan (which Beijing considers a renegade province) had to be routed via Hong Kong airspace, nearly doubling flight times from Shanghai. Opening up airspace can also one of the easiest steps that countries can make as they seek to end old squabbles. It is a kind of rapprochement that—unlike, say, tourist visits or trade—remains largely invisible to the population, and doesn’t elicit as many emotions, one of the reasons why the U.S. has been pushing for an airspace detente as a confidence-building measure between Israel and Gulf monarchies such as Saudi Arabia and the U.A.E. There is a precedent for that: In August 1994, months before Israel and Jordan signed a peace treaty and opened their borders, a Jordanian Boeing 727 was allowed to fly over Tel Aviv and Jerusalem on its way from London to Amman. The plane’s pilot: Jordan’s King Hussein, whose radio conversation with Israeli Prime Minister Yitzhak Rabin was broadcast live around the world. Write to Yaroslav Trofimov at yaroslav.trofimov@wsj.com