The resignation of Senator Sam Dastyari from the Labor frontbench as manager of opposition business in the Senate has become a circuit breaker on the matter of political donations in general and foreign donations in particular. If it had happened immediately the news broke it would have been a short-term cost to the Labor Party but a long term advantage in staking out a strong ethical position.

Opposition Leader Bill Shorten's reasons for not acting before Dastyari jumped on Wednesday were almost certainly mixed. He wouldn't have wanted to hand a victory to the Coalition. Internal Labor politics may have constrained his freedom to act. He may have believed the crime didn't merit that sort of punishment.

Much like Senator Arthur Sinodinos, Dastyari had to go under protest. Ironically both Dastyari and Sinodinos come from the same "backroom-boy" wings of their respective parties after careers as party official and adviser respectively. They should know better.

Dastyari deserved to lose his job. But the bigger issue is donations reform because political donations disfigure the political system. The government wants to isolate the Dastyari case from any bigger issues on the grounds that donations to an individual are different to donations to a political party. But the link between the two cannot be avoided.

The political parties don't want to touch the issue of political donations because it goes to the heart of the necessary role of big money in financing election campaigns. They depend upon them. Malcolm Turnbull describes the Dastyari controversy as Cash for Comment, like paid advertorials by radio shock jocks, because of Dastyari's pro-Chinese comments.

But the bigger issue is "cash for policy" - and that applies to both sides of politics because of the mix between election campaign donations and both access to and influence over policymakers in government and Parliament.

Chinese investment in Australia is in the news because of some recent restrictions imposed on it. That gives extra sensitivity to anything involving China. There is also a special edge to donations from Chinese entities. The tag of Manchurian candidate goes back a long way in Australian politics to Gough Whitlam's breakthrough visit to China in 1971 as opposition leader. The edge relates not only to the close state-business relationships in government-owned businesses in China but also to the history of the Red Peril and the Communist bogey in Australian politics. The tag "Chinese" is meant to scare us.

Before considering the future of foreign political donations in our political system, some extra reflection on what is involved is called for. Foreign donations to political parties may be only the tip of the iceberg. Political causes and interests are so entangled across the globe that money comes into Australia for all sorts of purposes. Any move towards regulation should consider whether it should apply to pressure groups, movements and lobbyists as well as to parties.

Some interventions come from business interests via multinational corporations and through influential business friends, whether they be British lords or American tycoons. Political commentary comes from foreign-owned media. The trade union movement has an international organisation, at present headed by an Australian, Sharan Burrow. Right back during the Great Strikes of the 1890s considerable international financial support flowed in on both sides to employers and unionists.

Foreign governments duchess Australian politicians in various ways, through their involvement in international study tours for future leaders and cross-party friendship groups for all MPs. From their point of view it is all about educating Australian parliamentarians in their country's history, society and culture. The Cold War was fought out in Australia in this way in the 1940s and '50s by the United States and the Soviet Union. There are similar foreign-government financed programs for travel, research and study by academics.

Nation-states lobby the Australian Parliament directly too. The first lobbying register, from 1983 to 1996, included a special Foreign section to recognise there was something special about it. Any big tender competition, such as the recent one to build Australia's submarine fleet, may be conducted between private corporations but these foreign governments, whether German, Swedish or Japanese, take a keen interest and engage in diplomatic lobbying in support of their own corporations.

All social policies also have an international dimension. This applies to a matter like same-sex marriage, which may be the subject of a plebiscite next February. Both sides in this debate, whether they are churches or secular organisations, are part of broad international movements and associations within which there is a free flow of money and personnel. It would not surprise if the plebiscite campaign had an international flavour as international speakers have already played a part in Australian debates.

Foreign interventions in Australian debates and controversies are commonplace. They are embedded in our political system. Both sides of politics not only partake in them but depend on them for business as usual. Any attempt to regulate these interventions therefore must take the form of cultural change.

Such change is difficult to bring about because it brings short-term pain for long-term gain. In our party political system it always takes two to tango but someone still needs to take the first step. That first step should be a circuit-breaker that will administer a positive shock to the system.

John Warhurst is an emeritus professor of political science at the Australian National University.

John.Warhurst@anu.edu.au