The Ugandan cable is the largest terrestrial network Facebook has helped construct in Africa and part of what the company describes as a broader push to connect the approximately 3.8 billion people who are still without internet around the world. The move comes as Facebook’s user growth slows in developed markets like the U.S. and Europe.

The social media giant’s presence on the continent remains small compared with other regions, but the Menlo Park, Calif.–based company said its strategy to get more people onto a faster and more robust internet will plug more of sub-Saharan Africa into the global economy.

Facebook has 131 million monthly active users from sub-Saharan Africa’s approximately 1.06 billion population, nearly all of whom access the platform via a mobile phone. In Uganda alone, the potential for growth is huge: just 42% of approximately 43 million Ugandans have a mobile phone, according to the Groupe Speciale Mobile Association. Google also has invested in fiber-optic cable in the capital, Kampala.

Critics say Facebook’s ventures into less-developed markets could undermine net neutrality by channeling traffic to its own platform and away from competitors. An earlier effort by Facebook to expand internet access in the developing world faltered in 2016, when India’s telecommunications regulator effectively banned the company from offering free access to a low-data version of Facebook and selected websites and apps. Governments across Africa—including in Uganda—are rolling back internet freedoms and cracking down on social media.

Facebook, which declined to comment on the cost of the Ugandan cable, says its Africa strategy is a long-term effort. Analysts say the lack of connectivity on the continent is a central impediment to increasing economic growth: Removing barriers to commerce and trade should create more opportunities for consumers to spend.

“It’s not a philanthropic venture. It’s a strategic investment with a long-term goal,” said Ebele Okobi, Facebook’s director of Africa public policy. “We see this as an enabler of our business, not as a way to gain advantages.”

Dexter Thillien, a London-based analyst with Fitch Solutions, said Facebook, conscious of the risks, is still testing the waters in Africa.

“It’s where they can make the least money, at least right now,” he said.

The word “Africa” appears just once in Facebook’s 2017 annual report, to inform readers that the continent is included, along with the Middle East and Latin America, under its “Rest of World” designation.

Still, on the ground in northwestern Uganda, which hosts about a million refugees from conflicts in neighboring South Sudan and the Democratic Republic of Congo, the fiber build has been cheered.

Duniya Aslam Khan, public information officer for the United Nations Refugee Agency, said improved connectivity has made a big difference in running the sprawling camps in the region. Refugees are better able to connect with family members back home, take online courses and, of course, join Facebook.

“Connectivity was a huge problem,” she said. “I’m speaking to you from my 3G mobile data, which was not possible a year ago.”

Since the fiber rollout, Airtel Uganda has installed 33 new telecom towers in northern Uganda, while 71 towers have been upgraded to 3G and another 43 towers now beam 4G, which improves users’ ability to download and stream quickly, the company said. Previously, most places in the region had 2G or no service at all—a far cry from developed economies, which are racing to roll out 5G networks. More than half of Africa’s mobile broadband connections remain 2G.

Beyond logistical challenges, Facebook must also manage political risks, including those concerning its responsibility for the content on its platform. The company has come under fire for its handling of hate speech and misinformation in countries with few other sources of internet access, such as Myanmar. An August U.N. report criticized Facebook for allowing leaders in the country to post content that investigators said inflamed ethnic violence against the Rohingya minority, a conflict the U.N. has deemed a genocide.

In July, Uganda imposed a tax on social-media use, which president of 32 years Yoweri Museveni blames for spreading “fake news” and gossip. Internet service providers, including Airtel, block social media sites until a tax of 200 Ugandan shillings (5 cents) a day is paid. Companies and analysts said the tax could exclude poorer consumers from accessing the internet at all.

“It’s unfortunate, because Uganda was making huge strides,” said Kojo Boayke, Facebook’s public policy manager for Africa. “When you look at an analysis of the tax, [it] would be $1.50 a month. It’s a huge proportion” of the average annual household income in Uganda of just $604.

Yet in far-flung Gulu, the arrival of faster, more reliable internet already has been transformative.

“That cable is fast for internet. That means communications will be much easier,” said Patricia Akello, project manager for Youth Alive, a Gulu-based provider of youth HIV counseling and testing. “Internet has become a necessity: Allowing young people access will educate them. They’ll be better able to prevent HIV…and they can be educators to others in the community.”