Before this year, Tobias Kammann, a German container ship captain, had only once sailed around the southern tip of Africa, and the lack of other vessels in the little-trafficked waters made him feel very much alone.

But these days, there are so many ships there, he said, that “it’s a bit like the autobahn.”

To get from Asia to Europe and back, global shipping companies have for decades sailed through the Red Sea and the Suez Canal. But a year ago, the Houthi insurgents in Yemen began targeting vessels in the Red Sea with drones and missiles, forcing shipping companies to divert their cargo around the Cape of Good Hope at Africa’s southern tip, a route that is some 3,500 nautical miles and 10 days longer.

Western-led naval fleets were sent to the Red Sea to quell the attacks, which the Iran-backed Houthis said were a response to Israel’s war on Hamas in Gaza. Despite those deployments, the attacks continued, and commercial vessels have, for the most part, stayed away. And Middle East analysts said they expected the Houthis to keep up their attacks even as Iran’s influence in the region has diminished after the weakening of Hezbollah in Lebanon and the collapse of Bashar al-Assad’s government in Syria.

It’s as if the shipping industry had been transported back to the days before the Suez Canal opened in 1869.

“This is one of the most significant challenges that shipping has faced in a long time,” said Salvatore Mercogliano, a maritime historian and an associate professor at Campbell University in North Carolina.