The announcement was made on Friday night US time. Questions have been raised in the US media whether the antagonism between US President Donald Trump and Amazon chief Jeff Bezos had anything to do with Microsoft winning the deal.
An AWS spokesperson said in a statement: "We’re surprised about this conclusion. AWS is the clear leader in cloud computing, and a detailed assessment purely on the comparative offerings clearly lead to a different conclusion.
"We remain deeply committed to continuing to innovate for the new digital battlefield where security, efficiency, resiliency, and scalability of resources can be the difference between success and failure.”
The DoD Joint Enterprise Defence Infrastructure contract, known by its acronym JEDI, is meant to unite all Defence services under one cloud vendor, as the CIA did in 2013 with Amazon at a cost of US$600 million.
The first draft calling for requests for proposals for the JEDI contract were put out in March 2018, with a formal proposal following after four months.
Apart from Microsoft and Amazon, Oracle and IBM were also in the running but the contest had been narrowed to two companies. Oracle went to court to protest what it saw as Amazon's being favoured for the deal, but met with no success.
Google, which also put its hand up for the bid, withdrew from the contest after many of its employees protested about its involvement. The search giant said it was pulling out because the JEDI deal was not one which would sit well with the company.
Trump's opposition to Amazon is no secret. In July, during a media appearance with the Netherlands Prime Minister Mark Rutte, Trump said in response to a question about the contract: "So, I’m getting tremendous complaints about the contract with the Pentagon and with Amazon.
"They’re saying it wasn’t competitively bid. And I will be asking them to look at it very closely to see what’s going on because I have had very few things where there’s been such complaining.
"Not only complaining from the media -- or at least asking questions about it from the media - but complaining from different companies like Microsoft and Oracle and IBM. Great companies are complaining about it. So we’re going to take a look at it. We’ll take a very strong look at it."
Update, 30 October: Toni Townes-Whitley, president, US Regulated Industries, Microsoft, responded to iTWire's query, saying: "For over 40 years, Microsoft has delivered innovative, proven and secure technologies to the US Department of Defence. We brought our best efforts to the rigorous JEDI evaluation process and appreciate that DoD has chosen Microsoft.
"We are proud that we are an integral partner in DoD's overall mission cloud strategy. As was articulated throughout the JEDI procurement, the DoD has a singular objective - to deploy the most innovative and secure commercially available technology to satisfy the urgent and critical needs of today's warfighters.
"We look forward to expanding our longstanding partnership with DoD and [to] support our men and women in uniform at home, abroad, and at the tactical edge with our latest unique and differentiated Azure cloud capabilities."