Hoang Thi Minh Hong had worried for months she could become the next environmental activist swept up in Vietnam's crackdown, so she closed her NGO and began keeping a low profile.

But it wasn't enough, and last month she became the fifth environmentalist jailed for tax evasion, in what activists see as a campaign to silence them.

Her conviction came less than a year after a group of donors, including the United States and European Union, pledged to mobilize $15.5 billion in funding as part of a Just Energy Transition Partnership (JETP) to help Vietnam switch to clean energy faster. The deal was hailed by U.S. President Joe Biden as part of Vietnam's "ambitious clean energy future."