Mr Trump has said he will pull the plug on his plans to build a large hotel, holiday homes and a residential village if an offshore windfarm within view of the luxury resort goes ahead.
He claims the 11-turbine European Offshore Wind Deployment Centre (EOWDC) will spoil the view from the course.
Lawyers acting for the US property billionaire are challenging the legality of the Scottish Government’s decision to approve the windfarm at the Court of Session in Edinburgh.
The golf resort would create between 4,000 and 5,000 jobs and cost at least £1 billion over seven years to construct, Gordon Steele QC told the court.
“This is something unique. It is unique in Scotland and it is unique in the UK,” he said.
“It requires the greatest possible attention and scrutiny in deciding whether or not all of that is to come to nothing, because it has been accepted that if this windfarm development proceeds in its current location, this resort will not proceed and the economy of Scotland will suffer significantly.
“This is a matter of importance not simply to the Trump Organisation but is important, in my submission, to the nation.”
The petition lodged by Trump International Golf Links and the Trump Organisation earlier this year asks the court to declare as unlawful the Scottish Government’s decision to approve the windfarm on March 26.
It also challenges the decision not to hold a public inquiry into the project in Aberdeen Bay.
James Mure QC, making the Scottish Government’s case, said an inquiry would have been of no benefit to ministers deciding whether to grant consent for the scheme.
Mr Mure said objections to the windfarm were properly considered throughout the lengthy planning process.
The Trump development was even given “preferential treatment” late on in the process to encourage its representatives to share anything they thought relevant and provided an “entirely clear” message about their objections.
“It was not a message which, in my submission, could have been clarified for (the Scottish ministers) by a formal inquiry,” Mr Mure said.
“It was entirely reasonable for the Scottish ministers to take the view that a public inquiry would not assist the ministers on the question of balancing and weighing up the policy interests which, at the end of the day, are at stake in Aberdeenshire.
“When it comes down to planning judgement, when there are policy interests the respondents have to have the final say, and an inquiry into matters, which the petitioners suggest, would not have provided any benefit.”
Mr Mure rebuffed an argument that a right to “peaceful enjoyment of property” under the European Convention on Human Rights was breached in relation to the Trump development.
The windfarm is not on Mr Trump’s land and does not affect rights under the planning permission, he said.
“They don’t specify any particular effect on their land, although we understand that there are visual impacts which are by no means minimal,” he said.
“In my submission, really no case is made.”
It has not been demonstrated that ministers breached their duty to consider all relevant matters, he said.
“I would invite the court to refuse the petition,” he concluded.
The court also heard from Douglas Armstrong QC, on behalf of windfarm applicants Aberdeen Offshore Wind Farm Ltd, referred to in legal papers as the “interested party”.
Previously Mr Trump’s lawyers suggested that the Scottish Government had financial involvement in the scheme because some parties received public funds.
“Throughout the process the interested party has been open about its background and where its financial support came from,” Mr Armstrong said.
The hearing before Lord Doherty continues tomorrow.