Operation Solidarity was the name for the United States peacekeeping mission to Wales in the summer and fall of 1952, during the English Anarchy. The operation was approved by President Prescott Bush in June and set into action in July, involving the amphibious landing of 20,000 Marines (2nd Division) in southern Wales on July 28, 1952, and the amphibious landing of 20,000 US Army soldiers (XI Corps) on the central Welsh coast. Shrouded in secrecy, the idea was to surprise any guerrillas and to stabilize Wales as a place of refuge for fleeing civilians; Bush enlisted the support of the Red Cross to use Wales as a staging ground to bring much-needed supplies into the war-torn country.
By most accounts, Solidarity was a muddled success. American troops quickly advanced through southern Wales and set up base in Cardiff, but suffered months of guerrilla attacks. An undeclared war with the Irish Regular Army was fought in central and northern Wales in September, notably at the Willows and culminated in the ferocious Welsh Storm, in which Irish and anti-American Welsh guerrillas, along with the nominal EWA, counterattacked and cornered the Americans at Cardiff, beginning Operation Welsh Fortress in November. Dislocated battalions of Americans eventually reached Cardiff in late November to puncture a hole through EWA and Irish lines, and the siege was called off in early December, giving the Americans a costly strategic victory. From then on, Cardiff became the primary base for aid landings, and Wales was reinforced in January of 1953 during Operation Falling Snow, which caught the surrounding forces off guard.
Solidarity and Welsh Fortress are regarded as parts of the Welsh Campaign, and were the last military operations authorized by President Bush.