Given the nickname "Chardonnay O'Brien" first by former prime minister David Lange and later by the New Zealand media for his love of a good glass of wine and a good cocktail party[citation needed], O'Brien was known for his global view and his articulation of the role of New Zealand as an independent and free-thinking country with its own values and way of doing things.

The Parliamentary Select Committee on Foreign Affairs, Defence and Trade investigated the matter and issued a critical report.

The book stresses the importance of New Zealand taking an independent view on international affairs, reflecting its heritage as a nation located in the south-west Pacific with both Maori and European roots.

In 2016, on the occasion of his 80th birthday, he established the Terence O'Brien Scholarship in International Affairs at Victoria University of Wellington in New Zealand.

During 2012, Terence O'Brien wrote several articles arguing against proposed reforms in the New Zealand Ministry of Foreign Affairs and Trade.

[3] His argument was that becoming a diplomat requires a special type of skill and that treating the Ministry of Foreign Affairs with a purely or even a mainly business approach was short-sighted and not to the long-term benefit of New Zealand.

Right up until mid-2021 when he suffered a stroke which limited his mobility, O'Brien continued to contribute part-time as an Advisor to the Centre for Strategic Studies and he was also a regular contributor to the New Zealand media on foreign policy issues.

[5][6] On 22 March 2023, Diplosphere organized an event in Wellington on 'Forging an Independent Foreign Policy for New Zealand: Terence O'Brien's imprint.