Here it is in a nutshell. China offered to build a port in Sri Lanka, promising more traffic then they could imagine and aid for their poor economy with a 99 year lease.
Port was built and hardly any traffic, less than 00.1% of what China led them to believe, though never in writing.

Now that Sri Lanka can't even make the interest payment, so China wants the port now by default.



Sri Lanka Wants to Undo Deal to Lease Port to China for 99 Years

Beijing has bankrolled infrastructure projects in dozens of countries as part of its Belt and Road Initiative, one of the biggest construction efforts in human history. The difference in Hambantota is that the Chinese state-owned operator physically took control of the port in late 2017 — on a 99-year lease — after the Sri Lankan government defaulted on its loans.

That has raised questions about sovereignty. An adviser to Sri Lanka's newly elected president recently said the government wants China to "give it back."

When U.S. and Indian officials accuse China of bullying poor countries with onerous loans, Hambantota is their oft-cited example.

"China uses so-called debt diplomacy to expand its influence. The terms of [its] loans are opaque at best, and the benefits invariably flow overwhelmingly to Beijing," Vice President Pence told the Hudson Institute, a think tank in Washington D.C., in October 2018. "Just ask Sri Lanka, which took on a massive debt to let Chinese state companies build a port of questionable commercial value. It may soon become a forward military base for China's growing blue-water navy."

Hambantota port may have been of "questionable commercial value" when it belonged to Sri Lanka. But its Chinese operators say that business is picking up. And they're set to control it for 97 more years.


https://www.npr.org/2019/12/13/784084567/in-sri-lanka-chinas-building-spree-is-raising-questions-about-sovereignty