Which Allied army officer deserves the lion share of the blame for the operational failure of Operation Market Garden in WW2?

First off, the operation was a military fiasco.  Let us know that and own that.  I do think that they chose to use the airborne which had been under utilized as a specialist force after D Day.  And just how well developed is airbourne doctrine anyway?

You have surprise which is lovely but it must be closely supoorted.  in this cae that close support had to fight their way foreward to be in support.  It sort of worked but then barely.  We ended up with the ignomious withdrawal back over the river.

Did this general have field experience?  Let him be remembered for this.

Which Allied army officer deserves the lion share of the blame for the operational failure of Operation Market Garden in WW2?

Lewis H. Brereton.

He was the airforce officer in charge of 1st Allied Airborne Army, and was in charge of carrying out Montgomery's orders for Operation Market – the securing of the route and the bridges leading to the East bank of the Rhine.

Despite being in command of several highy trained Airborne divisions he had no interest in ground warfare. As far as he was concerned the only thing he had to concern himself with was the air side of an operation – once the troops or supplies had left his aircraft his job was done. If enough missions were flown, enough troops and tons of supplies delivered, then the operation was a success, regardless of what happened on the ground afterwards.

Not only was he not interested in the ground battle, he wasn't interested in following his orders from Eisenhower. He only visited Montgomery's 21st Army Group HQ once, despite having been ordered to support Monty's advance, but visited Eisenhower's and Bradley's HQ's repeatedly. He didn't want to support the British and was much more interested in moving his command to Paris, with no thought of all the logistical problems that would cause, so that he could work with Bradley, despite Bradley having no interest in Airborne operations.

He inherited the plan for Operation Comet, which would have seen British 1st Airborne and the Poles capturing the bridges at Grave, Nijmegen and Arnhem with coup de main parties landing on both sides of the bridges, from Browning and then expanded it to use the 82nd and 101st US Airborne. All of the changes he made to the plan contributed to it's failure.

The Coup de Main parties. The only coup de main landing, at Grave bridge, was negotiated on the runway between the troops and their pilots – it wasn't part of the plan. That meant that the rest of the troops had to make an approach march to get to their objectives.

One daylight mission per day. The coup de main parties were supposed to land at night, as in Normandy, for maximum surprise followed by the main landings. Brereton changed that for a daylight drop, but also insisted on the slow build up of one landing or supply drop per day to save wear and tear on his planes and pilots

Holding the Drop Zones. The main drop zones had to be where they were – the terrain dictated that. But why sit and hold them rather than put your full strength onto the objective? Brereton's view was that holding the drop zones for later drops of troops and supplies was more important, since it made life easier for his pilots, than capturing and holding the ground objectives. That's why Gavin put more effort into holding the Groesbeek Heights than into capturing Nijmegen Bridge, and Urquhart put so much effort into holding his distant drop zones rather than moving immediately into Arnhem.

No air support. The landings were run from the UK with UK based fighters providing protection. To avoid confusion between UK based and Europe based aircraft (all of which had the same black and white ID stripes) Brereton banned Broadhurst's 84 Group (supporting 2nd Army) from flying while his transports were in the air, but that extended to when the those transports were grounded by fog in the UK. That meant that Spitfires and Typhoons were sitting on the ground in Belgium under clear skies while transports were sitting under fog in England and 1st Airborne were under attack in Arnhem.

No coordination. Broadhurst was horrified by the lack of communication between Brereton and 2nd Army. British Army and RAF practice was to plan their operations together, but Brereton never visited Dempsey's HQ and Broadhurst wasn't included in planning at all. The standard 21st AG practice of including forward air controllers with any army unit in an attack was unknown to Brereton and so the airborne troops were denied close air support. Hearing 1st Airborne calling for help over the radio and with his Typhoons sitting on the runways around Brussels ready to go, Broadhurst was informed by Coningham, his boss and enemy of all things army, that 'this operation is being run from England, and if THEY (ie Brereton) want help, THEY will ask for it'. 'THEY' never did.

In the end, once the last of 1st Airborne had been withdrawn over the Rhine and the casualties counted, Brereton counted the number of missions flown and the troops and tonnages delivered and declared Market Garden to be 'an outstanding success'. Others have their own view of the operation, and of Brereton.