Black tee-shirted Shore Patrol officers pop in and out of The Wolfhound, a popular Irish pub in the Haeundae beachfront area of Busan in South Korea, checking to ensure sailors from the USS George Washington are behaving themselves.
The aircraft carrier – along with the guided missile cruiser USS Antietam and guided-missile destroyer USS Preble – has just spent four days in the port on the southernmost point of the Korean peninsula, and the US Navy calls it "a routine port-of-call".
“During the four-day visit, US Navy personnel will have the opportunity to engage with Republic of Korea navy counterparts and participate in cultural exchanges and community outreach events with citizens from the Republic of Korea,” ran a Navy statement.
The ships are part of the George Washington Strike Group, which operates from Yokosuka, Japan.
But it's hard to see this visit as routine, given that it comes just days after South Korea staged its biggest military parade in a decade, displaying cruise missiles and torpedoes among a powerful arsenal in a potent show of strength aimed at neighbour and bitter rival North Korea.
Even here, in a seaside town which is about as far away as you can get from the demilitarised zone separating the two Koreas, it’s hard to forget the tensions that divide the peninsula. The two Koreas technically remain at war, as the 1950-53 Korean War ended in armistice, not a peace treaty, and the US commitment to defend South Korea is central to South Korea’s defence options. There are 28,500 US troops stationed here.
Washington's support
The relationship between South Korea and the US is complicated. While South Korea is a strong ally, there are occasional demonstrations about the US military presence, which jars with the broad recognition that the south still needs Washington's support as tensions with Pyongyang remain at a high level.
North Korea reacts sharply every time a US battleship arrives in South Korea, accusing the Seoul government and their US allies of warmongering. The North Koreans often say the reason they developed a nuclear weapons programme is to protect themselves against US-led militarism.
The Chinese government is also unhappy about the US bringing such high-profile vessels anywhere near their waters. One of the reasons Beijing is said to fear regime change in North Korea so keenly is that it could lead to a major US ally on its borders.
Earlier this year, US Naval Forces Korea broke ground on a new headquarters on a South Korean naval base, and Busan is a key part of American plans to establish its “Asian Pivot” in the region, which will see 60 per cent of American naval assets moved to the Pacific by the end of the decade.
Oliver Stone
As the US sailors strolled through the streets of Busan, they rubbed shoulders with global cineastes attending the city's annual film festival. Attendees were given leaflets protesting against plans to build a US naval base on Jeju Island, with Oliver Stone prominent among those opposing its construction.
The pamphlet showed the film director carrying a rainbow banner saying "Peace" during a demonstration in Gangjeong village on the tropical island off the south coast of South Korea. Many in Korea see it as a US attempt to dominate the region. "Ever since the second World War, the US has been building military alliances and setting up military bases overseas," Mr Stone told the Hankyoreh daily.
"A lot of those bases are in Japan and Korea. Jeju Island is less than 500 kilometres from Shanghai. It could end up on the front lines if a military conflict breaks out between the US and China, " he said.
North Korea carried out a third nuclear test in February, triggering months of heightened military tensions on the Korean peninsula, with Pyongyang threatening pre-emptive nuclear strikes on the south and the US.
At last week's parade, South Korean President Park Geun-Hye described the North's nuclear weapons programme as a "very grave" threat. Also watching the display, including the Hyunmoo 3 cruise missile, which Seoul says is capable of precision strikes on North Korean targets, was US defence secretary Chuck Hagel.
“The situation on the Korean peninsula . . . is very grave. North Korea adamantly continues to develop and upgrade its nuclear weapons,” Ms Park said in a speech to mark Armed Forces Day.
“Until North Korea abandons its nuclear programme and makes the right choice for the North Korean people and peace on the Korean peninsula, we should build strong deterrence towards the north,” she said.
The Shore Patrol officers look set to remain a familiar sight in South Korea’s ports of call.