So Mr Hockey goes to Washington. The former treasurer will take up his post at the Australian chancery on Massachusetts Avenue early in the new year.

Hockey's appointment, percolating through Canberra circles for months now, has drawn fire from several quarters. Conservative columnist Janet Albrechtsen classified him as 'one lucky bloke', hinting that his Falstaffian jollity will by no means suffice in one of the toughest, most demanding Australian posts abroad. Writing in The Australian Financial Review, Brian Toohey lamented Hockey's 'misplaced sense of entitlement' and argued that the prime minister should not have rewarded him with a 'lap of honour' in Washington.

Notwithstanding the cavalcade of political appointments to senior diplomatic posts in which both Labor and Liberal parties have indulged over the past half-century, the ledger of ambassadors to Washington boasts more than its fair share of those who arrive with the golden political handshake.

Excluding the early Australian representatives in Washington, who carried the rank of 'minister', Hockey is the eighth political appointment to the US capital since 1946. In September that year Ben Chifley nominated Norman Makin, who had been minister for the navy and then for munitions in the wartime Curtin government. Menzies appointed Percy Spender, and after him Howard Beale. Spender had served as minister for external affairs and conducted the negotiations that led to the signing of the ANZUS treaty in 1951: his credentials for Washington were unquestioned. But Howard Beale, with ministerial experience in supply, and transport and communications, brought with him limited experience of international affairs.

Malcolm Fraser sent the former Liberal party Senator Robert Cotton to Washington in August 1982. A member of the Gorton and Fraser cabinets, Cotton also had the benefit of a stint in New York as consul general before becoming ambassador. In more recent times, Paul Keating dispatched his chief of staff, Don Russell, to the position before recalling him early to direct Labor's 1996 election campaign. John Howard manoeuvred his long- time political rival Andrew Peacock there in early 1997, in so doing guillotining the term of one of Australia's most accomplished diplomats, John McCarthy, who had only arrived just over a year before. And Kevin Rudd appointed Kim Beazley in early 2010, a decision that enjoyed bipartisan endorsement.

But it is the timing of political and professional appointments that is perhaps most instructive.

Former politicians staffed the post from 1951-64, with Howard Beale presiding over arguably the most anxious period in the alliance to that time, as Canberra's disagreement with Washington over Indonesia's annexation of West New Guinea and Soekarno's policy of Confrontation towards the new Malaysian Federation exposed serious differences between the two countries over the meaning of ANZUS.

From 1964-1982, a period covering the Vietnam war, the promulgation of the Nixon doctrine, a metamorphosis in US China policy, and rancorous tensions between Richard Nixon and Gough Whitlam – the position was manned by professional diplomats: Keith Waller, James Plimsoll, Patrick Shaw, Nicholas Parkinson and Alan Renouf, all mandarins that had cut their diplomatic teeth in the post-war era.

Since 2000, the Washington embassy has been occupied by the tallest of diplomatic tall timber; Michael Thawley, Dennis Richardson and Kim Beazley. True, Beazley was a political appointment, but his wealth of experience in defence and foreign affairs, his intimate knowledge of the alliance and his absorption of American history made him uniquely qualified for the post, and he leaves Washington commanding enormous respect from Democrats and Republicans alike.

So if there is a question to be raised about Hockey it is whether the times demand another diplomatic professional. The commentary surrounding his appointment seems to suggest so. The relationship, as Beazley himself has pointed out, is becoming more complex as it becomes more critical. 'Australian influence in this town fluctuates', Beazley told one gathering late last year, and the Obama administration has not always proved a ready opener of doors for its close allies. Alliance management – for both the US and Australia – is becoming more difficult. Privately, some former senior US officials in Washington wonder whether a period of drift is in store for US-Australian relations. As one put it to me recently, 'if it can happen to the US-UK relationship, it can certainly happen to the Alliance'.

The biggest question, perhaps, for Hockey to consider is what kind of ally the US needs at this moment.

In giving thought to this matter, he should cast aside entirely the cloying, sycophantic speech given by his former leader to the Heritage Foundation in 2012, in which Abbott issued a plea for Americans to rediscover 'the belief in themselves'. And he might also disregard Julia Gillard’s similarly grating ‘Americans can do anything’ address to Congress the year before. History — and current sentiment in Washington — shows that the US appreciates much more a discerning, quietly critical ally than one which tries to massage a bruised psyche. Hockey will hear the drum beat of American nationalism throughout the presidential campaign, but the new administration he deals with come January 2017 will face the same constraints that Obama finds now in exercising American global leadership. Far better that an Australian ambassador seeks to encourage the prudent, realist strain in American foreign policy.

Indeed Hockey's greatest challenge may well lie in helping American officials realise that Australian governments might disagree with them with more frequency in the future. Whilst the speeches pronounced on the south lawn of the White House will continue to hail Australia as America's 'best friend' or its 'closest' ally, Australians cannot allow such flattery to overtake their judgment about where and when the nation should support the US, especially in Asia. To borrow from Owen Harries, Hockey will need to see beyond all this sweet talk and warm hugging.

Challenges, as ever, will abound. Beazley has had to manage Washington's hurt when Australia belatedly joined the AIIB, and frustration from US trade officials over Australia's stubborn demands on patent protections for new pharmaceuticals as part of the TPP. Hockey will likely have to continue the argy-bargy with the Pentagon on who will pay for the upgrade to the Darwin facility for the US marine rotation, and he will need to manage perceptions that Australian forces are becoming so integrated with their US counterparts that it potentially limits the policy choices open to Canberra.

On the South China Sea, the United States is not expecting Australia to join some kind of grand American-led armada to defend freedom of navigation, but it will welcome an Australia prepared to defend the same principles under its own steam; an Australia willing to push back against Chinese overreach when appropriate.

So subtle diplomacy, along with an acute understanding of the Australian national interest, a healthy scepticism towards uncritical alliance boosterism, and a keen eye for internal American arguments about US priorities, should be foremost in Hockey's mind as he takes possession of his new diplomatic passport.

Photo courtesy of Flickr user IMF