Spending 12 months at the Australian War College in Canberra isn’t exactly standard professional development for an accountant more used to boardrooms than battlegrounds, but for Bridget Marks FCA, it was a transformative experience.

As the deputy CFO at the New Zealand Defence Force (NZDF), Marks was selected to attend the professional military education program designed to develop mid-level military officers and selected civilian leaders in strategic thinking, leadership and defence management.

“War College was an incredible learning opportunity,” she says. “My cohort was primarily military leaders and included colonels from Australia, New Zealand, Canada, the UK, the US, and leaders from the Pacific and China.”

While there, Marks also completed a Master of Business Administration. On returning to New Zealand in 2018, she was appointed CFO of the NZDF.

In this role, she serves as the chief financial adviser to the chief of defence force, sits on the executive committee, chairs the organisational committee and manages the financial complexities across the entire defence organisation, including its highly sophisticated military systems.

But life as an accountant before public service beckoned was a different story, and one that prepared Marks for the pressures, pace and precision required at the highest levels of defence.

From spreadsheets to strategy

Marks’s path from the private sector to studying defence strategy began with a groundbreaking project she led as a finance manager at the NZDF, not long after joining the organisation following a 16-year career at Deloitte.

Starting in the Deloitte graduate program, she worked across strategic financial planning and advisory with more than 200 organisations, from small family-run businesses to mid-sized construction firms – and across both public and private sectors.

It gave her broad exposure to different industries and operating models, she says, and helped her develop a strong foundation in financial and strategic thinking, skills she draws on daily in her current role.

“Deloitte was great. I had children and was able to work part-time but when the time came to return to full-time work, I started thinking I wanted to try something different,” says Marks.

When a job as a finance manager at the NZDF came up, she jumped at the chance and found herself with the opportunity to lead the financial modelling for the Defence Midpoint Rebalancing Review. The team costed the component parts of the NZDF to 2030, from front-line military capabilities to the support elements of the organisation and created a long-term vision on how to deliver on the government’s policy expectations.

“For the first time, we calculated the real costs of things like sending a battalion into tough situations, protecting borders and patrolling the Pacific region,” she says.

“We analysed the costs of key capabilities the government wanted, which informed decisions on how to balance defence policy, capability needs and budget. It was an exciting project and something that had just never been done before.”

Navigating the public sector

While that experience gave Marks a rare insight into the operational scale and complexity of a modern defence force and grabbed her attention, moving into the public sector wasn’t without its challenges.

“It was a huge culture shock,” Marks says. “But I have found that providing advice across multiple business units is an interesting leadership challenge, given the complexity and the diverse nature of defence.”

Foremost among the challenges was adapting to the sense of purpose behind public service, as well as interpreting the language and culture.

“Public service is all about serving the greater good. You’re not managing for profit but for outcomes and that shift in purpose takes some getting used to,” she says. “Communication sometimes feels more like an order than a conversation, and ‘on time’ means arriving five minutes early for a meeting!”

Changing demands

As CFO, Marks is responsible for making sure the necessary resources to keep New Zealand safe are available, which requires long-term financial planning to secure consistent and reliable funding that supports operational readiness and strategic goals.

“Maintaining the NZDF’s reputation and upholding financial transparency are critical,” she says. “Especially when managing large, long-term asset acquisitions like P-8 [Boeing P-8A Poseidon] and C-130 [retired on 31 January 2025] aircraft fleets, and maritime renewal programs. These assets have lifespans ranging from 15 to 30 years, requiring careful financial management to optimise costs over their full lifecycle,” she adds.

“At the same time, the global situation is shifting and moving the NZDF from a mostly peacetime footing to one that requires faster capability upgrades.”

The current geopolitical pressures bring real financial challenges, including fluctuating foreign exchange rates, inflation, rising supply chain costs, delays in receiving critical equipment due to global disruptions, and difficulties maintaining stock levels of ammunition, spare parts and other essential items.

“It makes budgeting and procurement more complex and means we need to develop financial strategies to ensure the NZDF remains ready and capable,” she says.

A whole-of-defence view

One of the advantages of being a CFO is having visibility across the entire organisation. For Marks, this means bringing an enterprise-wide, systems-thinking approach to tackling challenges and risks.

“In defence, we have deputy service chiefs for the New Zealand Army, Royal New Zealand Air Force and Royal New Zealand Navy, plus commanders for logistics, estate and information command. Most issues need to be addressed across the whole organisation.

“Facilitating discussions that help operators, who often work in silos, lift their perspective to an enterprise level is something I really enjoy. It allows us to solve risks collectively.”

While many might find this complexity frustrating, Marks says she is glad she can bring people together and broaden their viewpoint.

“Think of it like an aircraft. You need the airframe, the pilot and crew, and the fuel to operate it. When any part faces cost pressure or issues, which are often managed by different managers, the mission can’t be delivered.

“Bringing these elements together, prioritising, and working through challenges is a part of the job I genuinely enjoy.”