The details concerning what the Government has and has not promised Nissan to keep them in the North East look bound to remain largely secret. It could, however, be the most important deal that they strike during the whole of the Brexit negotiations.
By doing the deal the Government has started to reveal what its plans are but critically, they have also shown other businesses and sectors what they might be prepared to do.
It could be argued that Nissan has a special place in the UK economy because of its importance to the whole of the economy in the North East - direct jobs, investment, and the whole supply chain as well.
If anything were to jeopardise the company's future operations then its impact would have be catastrophic.
For Theresa May, it would have been her 'coal mines moment'. She could not afford to 'shut down' a part of the country that still vividly remembers what Mrs Thatcher did during the 1980s.
For economic, social and perception reasons, this was a deal that Mrs May had to strike.
The UK told Nissan it would seek tariff-free access to EU markets for the motor industry as part of Brexit talks, the business secretary has said.Greg Clark said this statement of the government's objectives had helped persuade Nissan to boost its investment in the UK, securing thousands of jobs.Ministers have been under pressure to clarify the "support and assurances" Nissan said it received.