Jon Nazca / Reuters
A Spanish fisherman (R) speaks with members of the Spanish Civil Guard after they blocked his boat's path to the main site where an artificial reef was built by Gibraltar with concrete blocks, during a protest against this construction, in Algeciras bay, La Linea de la Concepcion in southern Spain August 18, 2013.
A pile of concrete blocks dumped into the sea has reignited centuries of tension between Britain and Spain over a rocky outpost at the mouth of the Mediterranean.
Three Royal Navy warships set sail for Gibraltar – a rocky outcrop connected to the Spanish mainland that was ceded to the U.K. 300 years ago – in a move described as "routine" by the British government but branded "gunboat diplomacy" by the press.
The latest diplomatic spat began late last month when the Gibraltarian government placed 70 concrete blocks off the 2.6 square mile territory's coast, claiming they were hoping to create an artificial reef for fish.
The move sparked fury in Madrid and the Spanish government accused Gibraltar of laying them "without the necessary authorization" in "waters that are not theirs."
“Spanish fishermen have fished there for years and the throwing of those blocks prevented them from doing so, so they have lost their revenue,” said Alfonso Barnuevo, the deputy spokesman for Spain’s Ministry of Foreign Affairs.
Within days of dropping the rocks, Gibraltarian officials accused their Spanish counterparts of increasing border checks and creating lengthy delays for the thousands of people who travel to and from the British overseas territory for both work and tourism.
Jon Nazca / Reuters
A driver sits on the roof of his car as he and other drivers wait in line to enter to Spain at its border with the British territory of Gibraltar on August 9.
After calling in Spanish Ambassador Federico Trillo for talks, a British government minister called the delays “unjustified and unacceptable.”
But Barnuevo denied that there was any connection between the concrete blocks being laid and the border checks.
“We are obliged to control (the border) in order to prevent illegal trafficking,” he said. “Smuggling is a very big issue, because you don’t know what is coming across.”
He added that Gibraltar, which governs itself but leaves defense and foreign policy to Great Britain, had not signed up to the Shengen Agreement, which permits people to travel freely between 26 countries on the European mainland.
Ratcheting up the rhetoric, in an interview with Spanish newspaper ABC Foreign Minister Jose Manuel Garcia-Margallo announced that he was considering a 50 Euro ($66) fee for anyone crossing the border from Gibraltar into Spain.
"The party is over for Gibraltar," he said, adding that Spain may also explore the possibility with Argentina of a "united front" at the United Nations, concerning Gibraltar and the Falklands.
Argentina is immersed in its own dispute with Britain over the sovereignty of the south Atlantic islands that Britain has ruled since 1833 and the countries fought a brief war over in 1982.
But Professor Damien Chalmers at the London School of Economics said he would be “very surprised” if Britain and Spain took up arms over Gibraltar.
“They are partners at the U.N., the European Union and the country’s have a history of cooperation,” he said. “I would be very surprised if they went to war.”
He added that he was sure that a diplomatic solution would likely be found.
The British government said it was considering their own legal action against Spain, citing European laws about freedom of movement.
The political posturing is just the latest round of diplomatic wrangling over Gibraltar – known as "The Rock" – since it was signed over to Britain in the 1713 Treaty of Utrecht, in return for their withdrawal from Spanish War of Succession.
By signing the document, Spain ceded "the full and entire propriety of the town and castle of Gibraltar, together with the port, fortifications, and forts thereunto belonging.... for ever, without any exception or impediment whatsoever."
“[Gibraltar] was one of the least important parts of that treaty,” said Dr. Chris Grocott, a lecturer at Britain’s University of Leicester. "The most important thing was stopping the war. There was all sorts of other stuff in there, like British rights to Florida, which have long since ceased to be important. Ironically it’s the thing now that’s still in play."
According to Grocott, who authored "Gibraltar, A Modern History," there was no mention in the treaty about territorial waters.
Marcos Moreno / AP, file
Spanish fishing boats sit moored in La Linea de Concepcion, Spain, in front of Gibraltar on May 28, 2012.
Although in the past Spanish armies laid siege to the territory, during the 20th century they have resorted to diplomatic methods in their attempts to claim the territory.
Citing two U.N. resolutions about territorial integrity, they have argued that Gibraltar’s location takes precedence over the provinces right to self-determination.
The British government points to referendums in 1967 and 2002 in which Gibraltarians voted overwhelmingly to remain part of Britain.
But despite the heated rhetoric, both countries agree that talks really are the best way to defuse the tensions.
"We prefer dialogue," said Barnuevo, the Spanish foreign ministry spokesman. "But we also have a certain number of legal measures to be in place."
For his part, Britain's Foreign Secretary William Hague said "a political solution" was needed to defuse the tension.
Andrew Cowie / AFP - Getty Images
Britain's helicopter carrier HMS Illustrious leaves Portsmouth naval base in southern England bound for the Mediterranean on August 12.
Reuters contributed to this report
This story was originally published on Sun Aug 18, 2013 9:42 AM EDT