I was once chatting to the owner of a colourful but tatty drinking establishment in Antigua. After a couple of bottles of what the locals called beer, he told me that he was AWOL from the British Army. His story was that he joined as a citizen of Antigua and after a few years, went home to visit his family. When arriving back in the UK, it transpired his Visa had expired. No problem he thought, I'll renew it now - at the airport. No chance, that type of Visa had to be issued by the MOD and he couldn't come in. No exceptions.
So he went back to Antigua, phoned his unit explaining the problem and was told to send them his passport so they could send it to the MOD and get the visa renewed. After nearly a year of phoning the UK and waiting for it to come back, the Army told him that he was now AWOL and to RTU immediately, despite the fact he had no passport - let alone a visa. They also stopped paying him.
As by now he was throughly bored of the whole situation and being none to partial to the British weather, he forgot the Army and opened a bar.
Water filled slit trench on Salisbury plain versus a bar on a beach in the Caribbean. Tough choice!