I would like to revive this thread by examining what were the root causes of the Axis failure to rout, expel, capture and or destroy the British in North Africa, the subsequent turning point @ El Alamein, and the wider consequences.
This is more of a discussion regarding the overall narrative strategic concepts rather than statistics and tonnage figures etc (which I will leave to those more qualified).
Here are what I deem to be the compelling reasons for the Axis defeat in North Africa and the Mediterranean and the resulting consequences, whilst keeping in mind the importance that Malta may have had on the situation in that theatre.
Firstly, the desert air force (RAF, etc) began to wrest air superiority by mid-1942 - Rommel himself stated that whoever controls the skies controls the battlefield.
Secondly, The British had secured their strategic position ( though tenuous ) in concert with the Soviets across the Middle East and had been 'managing' various colonies throughout the area for some decades, hence they had experience as well as a dominant presence, established infrastructure, and administrative systems in place. The reason I mention this is to challenge the 'what if' narrative that concludes that Rommel's capture of Cairo, Egypt, and the Suez would have been the end-game move. ( The British empire was still vast despite the numerous handicaps this would bring about)
Thirdly, the war of production was finally starting to affect the disparity on the battlefield (and morale).
Fourth, the loss of Rommel's 'good source', the capture of Nachrichten Fern Aufklarung Kompanie 621, and more widely the improving intelligence situation for the Allies as a result of 'Ultra'.
Lastly, a recurring situation that afflicted the Wehrmacht in many battles where they seemingly got to within a whisker of victory, only to find themselves overstretched, undersupplied, and outnumbered.
This is probably a combination of the negligent and inept if not non-existent Axis overall strategy for victory, a detailed blueprint for winning the war with clear objectives including cooperation between its 'allies', co-belligerents, etc. Germany's grand strategic blueprint was a vague, reactionary, and grandiose mix of ideology, planning on the run, hubris, and short-sightedness. There may have been many social, political, and cultural projects, but large-scale military planning with clear goals that were grounded in reality was vague at best and non-existent at worst.
North Africa started out as lending a helping hand to Italy with instructions to hold the British and prevent them from overrunning the Italians, again an egregious oversight proving to be a bad habit - Hitler and the high command only realizing its importance and reacting far too late by squandering precious men and materiel by way of Tunisia in 1943.
So the question's are: how many of these points could have been remedied?
Could the Axis secure the North African coastline, the Mediterranean, AND hold onto it?
If the Axis do succeed is it still strategically necessary to invade Russia?
The short answer is I believe they could have secured both by committing serious resources and focus - I gradually lose confidence in their ability to hold onto such a vast area unless Turkey joins, and the Axis take serious advantage of anti-British sentiment. Additionally what occurs in Russia has an important bearing.
Some, including myself, believe that the best strategy for the Axis in Europe, specifically Germany was to stick to the Prussian military tenets of Schwerpunkt, Bewegungskrieg, Kurz und vives, Auftragstaktik - most importantly concentrating on one front/theatre at a time. What other choice do they have?
I believe that the Germans erred badly by treating North Africa as a sideshow.
I also believe (however impractical), that North Africa and the Mediterranean ought to have been dealt with BEFORE Russia.
And before anyone starts shouting, Germany ended up fighting not a two-front war, but a multi-front war which proved to be the winning formula, similar to the defeat of Napoleon. One-on-one the Germans proved superior, so stretch them to breaking point by creating fronts all over the continent.
If one includes the air and the sea as separate theatre's then Germany ended up fighting at a minimum a three-front war on land and additionally an air war, sea war, intelligence war, which all impacted Germany's ability to produce and provide itself with adequate resources.
If this is to be accepted, then Malta was of great importance to the Axis, not to mention Gibraltar ( a tough assignment as it meant risking relations with Spain ) and also commandeering the French fleet before the British attacked it.
At a minimum Malta would have greatly increased the security of Axis shipping and thus supplies, which ultimately tipped the battle in the Allies' favour. However, the Axis were running on a countdown clock - they had to secure the important strategic objectives enabling them to prosecute the war on their terms before the Allies production output cancelled any and all opportunity to either win or force a long term conflict.