Barilaro's threats to take the Nationals from the government benches to the crossbench over his objections to the government's koala habitat protection legislation is just the most recent of his many threats. Berejiklian called his bluff and insisted that the Nationals' remaining as ministers while sitting on the cross-bench was not possible and Barilaro backed down, while absurdly claiming victory. A general pile on between members of the two parties ensued.

What is going on? There are many alternative explanations. Is this just some harmless theatre of the absurd to entertain the masses? Is it a coolly calculated strategic manoeuvre to enable renegotiation of the legislation behind closed doors over the cabinet table? Does the Nationals' core support in rural and regional Australia need a regular demonstration of the party's supposed virility and independence regardless of the consequences? Is Barilaro a one-off problem of an unstable leader gone wild with power?

There are elements of all four alternatives in any convincing explanation. Put Barilaro in context. We have seen variations on this theme throughout the last 100 years of Australian political history. He represents an endemic issue in Australian politics and a perennial problem for Liberal-National relations in every jurisdiction where the Coalition exists.

The Coalition arrangement is a strange beast. Viewed from one perspective it is an enduring rock-solid element of Australian politics. The coalition between the Liberal and National parties is so solid that it is almost more than a coalition, a life-long bond between two sibling parties. Years ago, a political scientist picked up this theme and described Australia as having a two and a half, not three, party system.

It is effectively a coalition in government and opposition, despite occasional exceptions, a marriage which is not threatened by other suitors. It just happens like clockwork each time the conservative side of politics wins an election. It is, of course, just one party, the Liberal National Party, in Queensland, making the federal Coalition an even stranger beast.

Viewed from another perspective the Coalition is built on sand, not rock. The two parties have different histories, constituencies, interests and geographical roots. This makes for a hard-headed business arrangement rather than a marriage made in heaven. It recognises the essential economic and social differences between urban Liberals and rural Nationals. Holding the Coalition together demands a contractual agreement and compatible leaders. The federal Coalition is based on a written agreement renegotiated between each succeeding Liberal Prime Minister and the Nationals. Relations can be shaky and even break down.

The first perspective brings to mind strong Coalition leadership teams, like Malcolm Fraser and Doug Anthony or John Howard and John Anderson. The second evokes Joh Bjelke-Petersen, who tried to crush the Liberals in Queensland, or lately Barnaby Joyce. Barilaro clearly fits into the second model of Coalition relations.

The Liberal-National Coalition is so much part of the political furniture that the sort of recent eruption in NSW can take us by surprise. But it shouldn't. There are just as many forces driving the two parties apart as bringing them together. In the hands of personalities like Joyce or Barilaro there will be regular disruption to effective coalition relations.

A useful parallel is to imagine coalitions between Labor and the Greens, where the outcomes range between effective and sustainable in the ACT and ultimately unworkable in Tasmania. But Labor and the Greens have just as much in common as Liberals and Nationals. In both cases they have some ideological overlap and compatible interests while remaining fierce competitors with distinct personalities.

At the heart of the dilemma for Nationals leaders like Barilaro is that invariably the Nationals are the junior partner in the Coalition. In NSW they are less than half the size of the Liberals. This means that unless they can be the tail wagging the dog they are perpetually in the minority within the government.

Coalition government gives them status and perks that they cannot achieve on their own. First among them is ministerial office, including the high office of Deputy Premier. They have responsibility for key portfolios relating to rural and regional NSW, but policy is made finally in cabinet, in which they are in a minority. This is the trade-off.

This can be an uncomfortable situation to be in and requires some sense of humility and recognition of their subordinate position. The "little brother" must put up with "big brother" assuming majority rights in the direction taken by the government. Explaining their relative impotence to their own supporters is never easy. Cabinet solidarity and secrecy makes it harder for the Nationals to talk up their own achievements, because they are not independent but the junior partner in a conservative coalition. The majority in Cabinet rules.

There is always an alternative option for the Nationals, which is sitting on the crossbench, guaranteeing support for the government, while trying to negotiate the best outcome each bill at a time. No ministries, but the freedom to speak up and to behave like an independent party. Leaders such as Barilaro seem better suited to this approach.

Such an alternative will always be an attractive dream, but in the harsh light of reality the Nationals generally retreat to the safety of the Coalition with all its benefits despite all its restrictions.