This month, Sri Lanka, unable to pay the onerous debt to China it has accumulated, formally handed over its strategically located Hambantota port to the Asian giant. It was a major acquisition for China's Belt and Road Initiative (BRI) — which President Xi Jinping calls the "project of the century" — and proof of just how effective China's debt-trap diplomacy can be.

Unlike International Monetary Fund and World Bank lending, Chinese loans are collateralized by strategically important natural assets with high long-term value (even if they lack short-term commercial viability). Hambantota, for example, straddles Indian Ocean trade routes linking Europe, Africa and the Middle East to Asia. In exchange for financing and building the infrastructure that poorer countries need, China demands favorable access to their natural assets, from mineral resources to ports.

Moreover, as Sri Lanka's experience starkly illustrates, Chinese financing can shackle its "partner" countries. Rather than offering grants or concessionary loans, China provides huge project-related loans at market-based rates, without transparency, much less environmental or social impact assessments. As U.S. Secretary of State Rex Tillerson put it recently, with the BRI China is aiming to define "its own rules and norms."