'Aggression' was a British naval movement of reinforcements to the west along the North African coast from Alexandria in Egypt to Tobruk in the Cyrenaica area of the Italian colony of Libya (18/27 November 1941).

The naval operation was designed to aid the successful implementation of the 'Crusader' (i) land offensive, which started on 18 November with the primary objective of relieving Tobruk. To support the operation through the simulation of a supply convoy from Alexandria to Malta, elements of Admiral Sir Andrew Cunningham’s Mediterranean Fleet departed Alexandria to the west with an escort provided by the destroyers Napier, Nizam, Kipling, Jackal, Kimberley and Kingston. On 19 November Kipling and Jackal undertook a gunfire bombardment of Axis targets around the Halfaya Pass east of Tobruk.

A second diversionary operation was launched on 21 November. On this day Major General R. M. Scobie’s 70^th Division, which constituted the core of Tobruk’s garrison, broke out to the east in an effort to meet the leading formations of Lieutenant General Sir Alan Cunningham’s 8^th Army. To supply Tobruk, the Australian sloops Parramatta and Yarra were meanwhile escorting a slow convoy to Tobruk between 18 and 23 November. On 22 November the light anti-aircraft cruiser Carlisle departed Alexandria with three destroyers to escort the 9,784-ton landing and logistic supply ship Glenroy carrying military personnel and stores to Tobruk. On the following day this group of ships came under Axis air attack, and Glenroy was struck by a torpedo and seriously damaged. The ship was taken in tow by Carlisle, which later passed the task to the escort destroyer Farndale. Glenroy had to be beached to the west of Mersa Matruh, however, but was later refloated and taken in tow by tugs from Alexandria.

In order to alleviate the garrison’s shortage of ammunition, Parramatta and the escort destroyer Avon Vale then escorted the 1,360-ton ammunition transport Hanne to Tobruk, but Kapitänleutnant Hans Heidtmann’s U-559 torpedoed and sank Parramatta off Tobruk on 27 November.