London struggles to make sense of seizure
Whether Iran seized British servicemen by accident or design, the action is likely to be seen as a sign of displeasure from the theocratic regime and its foot soldiers, the Revolutionary Guards.
The Iranians were furious at Britain's involvement in drafting last week's resolution by the International Atomic Energy Agency, the United Nations nuclear watchdog, rebuking Tehran for covering up part of its nuclear operations.
That has created suspicions that Iran is secretly seeking to produce nuclear weapons.
Iran was so angry that its chief nuclear negotiator said it would "reconsider" its decision to suspend uranium enrichment, an essential process in the development of nuclear weapons.
There are other reasons to suspect something sinister in the detention. The involvement of the Revolutionary Guards, a branch of the armed forces charged with defending the Islamic revolution, may mean traditionalist religious elements are seeking to send a message to London.
On Monday British officials were trying to make sense of the detention. "Unless Iran hands back the boats within 48 hours, this could erupt into a huge diplomatic crisis," one said.
But the incident could be little more than a combination of poor map reading by the British and an over-zealous Iranian commander.
The Ministry of Defence noted that the border between the two countries was not always clear on the Shatt al-Arab south of Basra.
Britain has painstakingly rebuilt relations with Tehran over more than 20 years since they were ruptured by the Islamic revolution.
London has frequently disagreed and occasionally clashed with Washington over what some Bush Administration officials see as appeasement. Washington, which placed Iran in its "axis of evil", suggests that Britain's attempts to maintain a dialogue have brought few political or diplomatic dividends.
Britain insists the contacts have produced concessions, particularly Tehran's agreement to abide by the nuclear non-proliferation treaty and permit stricter UN inspections. Exiled Iranians see the policy of "constructive engagement" as too cosy and some experts suggest that Iran sees Britain's efforts to engender friendly relations as a sign of weakness.
Certainly Tehran seems to delight in posturing aggressively at the slightest opportunity.
Mistrust of Britain goes deep, harking back to the days when the Shah of Iran maintained a close relationship with the British royal family.
The Iranian establishment is convinced that Britain is waiting to exploit signs of weakness in the Tehran leadership and that its policy of dialogue is designed to make it easier for London to interfere in and influence Iran's internal affairs.
The Telegraph, London