British Diplomatic Oil Crisis: Contemporary Anglo-Saxon Geopolitical Rivalries in the Persian Gulf: Drawing a Lesson? Or Sir Anthony Eden‘s Delusion of Grandeur.

The
owners of the tanker, the Compania de Navigacion Teresita firm,
controlled by an Italian with the name of Rizzi, were at once
approached by the Anglo-Iranian Oil Company, which persuaded them to
transfer to the Anglo- Iranian Oil Company the charter held by the
Bubenberg Company. As the tanker was navigating the south coast of
Arabia, Royal Air Force planes circled round the vessel, until
eventually they managed to divert the tanker to Aden, where it was
under British jurisdiction. On 10th December 1952, ultimately the
case came up for hearing before the Aden Supreme Court. Sir Hartley
Shawcross, the former Attorney-General, had been briefed by the
Anglo-Iranian Oil Company to conduct the case. On 9th January 1953,
the Court ruled that the oil belonged to the Anglo-Iranian Oil
Company and was to be surrendered immediately.

Apart
from the oil blockade, and direct action against ‘freelance
ventures, of which an example has just been given, the British
Government as early as June 1951 started to impose economic
sanctions on Iran, as was said in Chapter Three.6 The export of sugar, steel, iron,
non-ferrous
metals, alloys, railway trucks, and materials became forbidden:

We should
prevent the export to Persia of sugar, and other
commodities which clearly result in a direct or indirect loss of
dollars to the United Kingdom.7

Any
vessel which carried such goods to Iranian ports would be
diverted, by radio, even if contracts had already been made, without
taking any notice of Iranian officials’ complaints.