The retirement to the Hindenburg Line took place Process_start as part of the ( Operation Alberich/Alberich Manoeuvre ) from February to March 1917 , after local withdrawals on the Somme had been forced on the 1st Army by British attacks Attack up the Ancre valley in January and February .

Some observers were critical of the tactics used Using ; the `` Boston Herald '' described Statement the service withdrawals as evidence of `` how very powerful these cyber-bullies can be . ''

In the subsequent battles Hostile_encounter and withdrawals Escaping during the period of November 26 to December 2 , 1950 , although the US Eighth Army managed Control to avoid Preventing_or_letting being surrounded Surrounding by PVA forces Causation , the PVA 13th Army were still able to inflict Causation heavy losses Earnings_and_losses onto the retreating Escaping UN forces which had lost Earnings_and_losses all cohesion .

German troop withdrawals Departing to reinforce Cause_change_of_strength the main armies in France were postponed Change_event_time to repulse a Belgian sortie from 9 to 13 September and a German corps in transit Motion was retained Preserving in Belgium for several days .