To comment more generally, Myanmar has probably the most enviable geopolitical _potential_ in the region if the not the world. It's the only country that can land connect China/India, has deep shore potentials that would wreck maritime trade patterns in the region... which contains 1/2 of the worlds population and is rapidly developing economically. It's almost in everyone's external interest to control Myanmar, or see it in dysfunctional shambles to create environment subject to easy influence.

Having long-term military basing there by US or China would be... strategically significant and only IMO possible via invasion. That applies to military basing in the region in general, too much colonial history and political baggage for anything other than logistics support during peace time.