Today, both Thailand and the United States face stalemate in addressing serious environmental problems. The lack of policy action seemingly occurs, in both countries, because of an unwillingness on the part of government to address the problem. Yet, we know there are instances of “punctuated equilibrium” or significant policy movement that upsets status quo arrangements and causes government to act. This research uses a case study approach and a Most Different Systems Design to study movement, or gridlock, in environmental policy in two countries half a world apart. By studying both successes and failures, in distinct socio-political settings, we are able to uncover systematic explanations for environmental policy progress. Specifically, we learn that political and public consensus is crucial for environmental policy success. Moreover, we learn that vested business interests often hinder policy advancement. Last, we learn that environmental interest groups and international pressure are neither necessary nor sufficient to produce policy change.