Significance
This is the first visit to Washington by a Thai prime minister since 2005. Thai-US relations have been much cooler since the mid-2014 military coup that Prayuth, as an army general, led to depose Prime Minister Yingluck Shinawatra. The visit, therefore, had high symbolism. It was also controversial because Trump is warming ties with a coup leader who has instituted a new constitution that will weaken elected government in Thailand after the next election, which Prayuth told Trump would take place in 2018.
Impacts
Thailand’s election could be delayed to 2019: two of the required pre-poll ‘organic laws’ will not be passed until end-2018.
Thai intellectual property protections will likely be strengthened to avoid sanctions under the US Trade Act’s Section 301.
Thai-US anti-Islamic State cooperation will likely be slow to build, partly given southern Thailand’s Muslim-Buddhist conflict.
Thailand will push for enhanced trade ties with the EU and post-Brexit United Kingdom.
The Analysis of Section 301's of the US Trade Policy in International Trade and The Impact to GATT Rules (What Can be learned as an Indonesian Trader)