Australia's Ambassador in Washington, Kim Beazley, recently said that Australia's alliance with the US had reached a level of importance greater than during the Cold War, and more akin to its crucial importance during World War II. Recent developments in the realms of security and trade, however contested, seem to underline his claims. This at a time when change is coming for Australia's representation in Washington. Coming months will see increasing speculation over who will succeed Beazley, whose extended term expires at the end of this year.

The situation gives pause for thought: what kind of attributes do we look for in Australians who can serve as Ambassador to the US?

Kim Beazley presents his credentials to President Obama, January 2012. (White House.)

At one level, the question logically incorporates generic qualities of those who are suited to serve anywhere overseas and represent Australia's interests. And the desired traits – among them, integrity, energy, acumen, fine judgement, high powers of observation and interpretation, advanced interpersonal and relationship-building skills – are, we trust, cultivated within DFAT. But with certain posts, such as London, Paris and Washington, the question takes on another dimension due to the frequency of appointments from outside the Department, and primarily from the ranks of retiring politicians.

In the case of Washington, the question of who best serves the government's representational needs is especially timely for reasons that invite looking back as well as forward. This year marks the 75th anniversary of Australian diplomatic representation in Washington. From 1940, when RG Casey headed the new Legation with a staff of five, the Embassy (embassy status came in 1946) has grown to boast more than 250 staff today, and the building is about to be rebuilt to meet expanded needs.

The work of Australia's senior diplomats in Washington was the subject of a two-day seminar held at Deakin University in October last year, the results of which will be published soon. Certain patterns emerged from the exercise, including the long-term profile of ambassadors.

Beazley, of course, is a former Labor Party leader. Before him were two senior public servants who were trained in External Affairs/DFAT, Michael Thawley and Dennis Richardson. Before them was former Liberal Party leader, Andrew Peacock. The mix is the same when surveying Australia's Ambassadors over the whole 75 years: of the 20 Australian ambassadors to the US*, ten have been professional appointees, moving to Washington either directly from External Affairs/DFAT or from another senior public service post, and ten have been from beyond the career service**: seven former politicians, one judge, one diplomatically experienced public servant (Frederic Eggleston) and one senior public servant in Don Russell, who emerged not from DFAT but Treasury prior to his becoming principal adviser to Treasurer Paul Keating.

There is great variety among those who have held Australia's most senior post in Washington. Our first, Richard Casey, has been described as a model diplomat, winning confidences and networking brilliantly with Washington's policy-making elite in the early 1940s. His successor, former Labor politician Norman Makin, was an abstemious man whose integrity was admired, but who hated the cocktail circuit and was reluctant to engage on key policy issues. Makin's successor, Percy Spender, former senior politician in the Liberal Party and Australia's most activist ambassador, loved Washington parties as much as he loved the idea of being a second Australian Minister for External Affairs, telling Canberra what to do.

In other words, even between three early political appointees, the variability between ambassadors makes it clear that the professional/political line has limitations as a means of distinguishing the characteristics and performances of Australians in Washington.

Similarly, during the turbulent years from the mid-1960s to early 1980s, Australia's ambassadors were the cream of the Department's professional diplomats, including three former permanent secretaries: Sir James Plimsoll, Sir Alan Renouf and Sir Nicholas Parkinson. Yet their experiences varied hugely, with the consequences of withdrawal from Vietnam, searching questioning of the ANZUS Treaty and difficult dynamics between the two countries' leaders shifting the ground beneath their feet.

Among the themes to emerge from the October 2014 seminar, which featured former senior members of the embassy, was the rise of Congress as a focal point for Australian diplomats and the relative decline in opportunities for meeting with Washington's most senior members of government. Instead of Percy Spender advancing Australia's interests in the 1950s over one of his semi-regular dinners with US Secretary of State John Foster Dulles, today Ambassador Beazley might work hard to meet with a Congressional power-broker in relation to legislative measures affecting Australia's interests.

While discussion did not focus on the issue of political vs professional appointees, it was a question that was never far from the surface, and one that looms more prominently now, thinking towards Beazley's successor.

One former senior Embassy official has suggested that we might do well to tilt the balance towards professional diplomats: to the extent that ambassadors can be agents of change, diplomats' agendas tend to more ambitious and longer-term than former politicians', especially when the diplomats are not at the end of their careers. Against this view, some would argue that gravitas matters a great deal in Washington and former politicians bring a lot of this with them. If the Abbott Government is going to ready us for an announcement some time soon, we might start to see traces of one or other of these views.

* This includes the three Ministers of the Legation between 1940 and 1946: Casey, Owen Dixon, and Frederic Eggleston.

** While I have counted Casey as one of the non-career appointees, on the basis of his having been an elected member of Australian governments prior to his posting, he could also be said to represent professional diplomats, having served earlier and very successfully in Australia's High Commission in London, before a professional Australian diplomatic service existed.