Insights: A warning years in the making catches up with Denmark’s F-35 programme

The reaction from Danish politicians was largely as expected.

The Auditor General’s Office (Rigsrevisionen) concluded on Monday that the total cost of the country’s F-35 acquisition programme is likely to be around DKK 14 billion (2017 prices) higher than previously stated by the Ministry of Defence.

For industry, the more immediate concern is that the increase could affect funding available for other procurement programmes, potentially reshaping acquisition priorities across the Danish defence portfolio.

Politicians nevertheless responded with predictable frustration.

- We are being held hostage, a representative of the Liberal Party told TV 2 following the report’s publication.

For those who have followed the programme over many years, however, the findings are hardly surprising. Rather, they reflect concerns that have been raised repeatedly throughout the aircraft’s development and procurement history.

Over time, numerous warnings have highlighted the risk that the F-35 programme could become a significant burden on national defence budgets. Both Danish defence officials and politicians have long been aware of those concerns.

The warnings have come from government accountability bodies, independent industry specialists and defence analysts. Information about the programme’s cost challenges has been publicly available for years.

The US Government Accountability Office (GAO) has published critical reports for many years, repeatedly warning of rising acquisition costs and escalating sustainment and maintenance expenses.

In the United States, the programme’s total lifecycle cost is expected to exceed USD 2 trillion over its projected 77-year lifespan. GAO assessments have also found that sustainment costs have increased by 44 percent.

The UK National Audit Office has likewise warned that the full cost of Britain’s F-35 fleet would be substantially higher than originally forecast as support, infrastructure and operating costs became clearer over time.

Dutch and Norwegian audit authorities have also questioned long-term operating and sustainment assumptions associated with the programme.

According to Rigsrevisionen, rising sustainment costs are also the primary driver behind the increase in Denmark’s projected expenditure, and the auditors have raised concerns before.

In a 2017 report examining the decision-making basis for Denmark’s fighter aircraft acquisition, Rigsrevisionen noted that the case for purchasing the F-35 rested on "uncertain financial assumptions".

"At the time, we assessed that this created a risk that the Ministry of Defence would be unable to carry out all the planned operational tasks with the fighter aircraft within the allocated budget framework," the auditors stated in their latest report.

Despite those warnings, Danish politicians approved the acquisition of an additional 16 F-35 aircraft in October 2025.

The principal concern, as Rigsrevisionen notes, is that higher F-35 costs could place pressure on funding for other procurement programmes within the Danish armed forces.

The timing is particularly sensitive given Denmark’s long record of troubled defence procurement projects.

Although Prime Minister Mette Frederiksen has urged the armed forces to “buy, buy, buy” in response to the deteriorating European security environment, confidence in the defence establishment’s ability to manage major acquisitions remains under scrutiny among both politicians and the wider public.

The latest report is unlikely to ease those concerns.

According to Rigsrevisionen, the Ministry of Defence had been aware of the cost increases for a decade without providing Parliament with a transparent picture of their long-term implications.

The criticism from the auditors is unusually direct:

"Over a 10-year period, the ministry significantly underestimated total costs by around DKK 14 billion in 2017 prices, and the information about the purchase that the ministry passed on to the Danish parliament did not provide transparency over the costs."

What the findings will ultimately mean for other procurement programmes remains unclear. 

However, the risk is that a larger share of future defence spending will be absorbed by sustaining the F-35 fleet, leaving less funding available for other modernisation priorities.

For now, Denmark’s new defence minister, Social Democrat Jeppe Bruus, begins his tenure facing a significant challenge inherited from his predecessors.