Repairs were completed in December and Theodor Riedel participated in the Battle of the Barents Sea at the end of the year and in the German attack on Spitzbergen in mid-1943.

Theodor Riedel spent the rest of the year under British control as the Allies decided how to dispose of the captured German ships and was ultimately allotted to France in early 1946 and renamed Kléber.

[2] Theodor Riedel carried a maximum of 752 metric tons (740 long tons) of fuel oil which was intended to give a range of 4,400 nautical miles (8,100 km; 5,100 mi) at a speed of 19 knots (35 km/h; 22 mph), but the ship proved top-heavy in service and 30% of the fuel had to be retained as ballast low in the ship.

The division accompanied the heavy cruiser Admiral Graf Spee on her voyage to the Mediterranean in October where they visited Vigo, Tangiers, and Ceuta before returning home.

[10] The ship attempted to lay a minefield off the British coast on the night of 12/13 November, with two of her sisters, but had to turn back after she and Z7 Hermann Schoemann suffered machinery breakdowns.

On 22 February 1940, Theodor Riedel and five other destroyers, Z3 Max Schultz, Z1 Leberecht Maass, Z4 Richard Beitzen, Z13 Erich Koellner and Z16 Friedrich Eckoldt, sailed for the Dogger Bank to intercept British fishing vessels in "Operation Wikinger".

Hitler ordered a Court of Inquiry to be convened to investigate the cause of the losses and it concluded that both ships that been sunk by bombs from the He 111.

[13] Postwar evidence revealed that one or both ships struck a British minefield laid by the destroyers Ivanhoe and Intrepid.

[15] Theodor Riedel and her sisters Z8 Bruno Heinemann and Z5 Paul Jacobi each carried a company of mountain troops tasked to seize the forts defending the entrance to the Trondheimsfjord.

All of the destroyers had suffered storm damage en route and were low on fuel because none of the oil tankers had arrived yet.

To defend the port after Admiral Hipper departed, Theodor Riedel was beached on a sandbar on 10 April as a stationary artillery and torpedo battery.

There she was the first German destroyer to receive a FuMO 21[Note 1] search radar[17] and one set of torpedo tubes was removed and remounted on land near Agdenes to improve the local defenses.

She departed for Norway three days later,[10] but struck an uncharted reef that ripped open her bottom in seven compartments and caused both propeller shafts to seize up.

[10] Theodor Riedel departed for Norway on 11 June and she was one of four destroyers assigned to escort the battleship Tirpitz during Operation Rösselsprung (Knight's Move), an attack on the Russia-bound Convoy PQ 17.

The ships sailed from Trondheim on 2 July for the first stage of the operation, although three of the destroyers, including Theodor Riedel, assigned to Tirpitz's escort ran aground in the dark and heavy fog and were forced to return to port for repairs.

Coupled with the damage suffered by the heavy cruiser Lützow when she ran aground the same day, the operation was canceled shortly afterwards.

[23] Theodor Riedel escorted the minelayer Brummer in early February 1943 as the latter laid a minefield near Kildin Island in the Barents Sea.

The following month, the ship, her sister Paul Jacobi, and the destroyer Z20 Karl Galster sailed for Jan Mayen island on 31 March to rendezvous with the blockade runner, MV Regensburg.

Theodor Riedel then sailed for Trondheim for repairs, but was nearly lost en route on 6 April when water contamination of her fuel caused her to lose all power.

While successful, the operation was primarily intended to boost the morale of the ships stationed in the Arctic when fuel shortages limited their activities and the Allies reestablished the bases five weeks later.

Theodor Riedel remained in Southern Norway and Denmark until the ships there were ordered into the Baltic to assist with the evacuation of the Hel Peninsula on 5 May.

Now assigned to the 3rd Destroyer Division of the Mediterranean Fleet, the ship made numerous port visits in French North Africa over the next two years.