I've done a deep-dive into the concept of the National Cabinet, and how it fits with the traditional Cabinet in the Westminster and Australian federal systems. Here are some thoughts.

1. Departments of State were once led by separate Ministers, each responsible for advising the Crown in respect of that Department. Ministers came and went individually, not collectively, and the Crown decided who to keep and who to sack.

2. Cabinet formed as a Committee of the Privy Council, as means for the Ministers to meet and discuss advice to be given to the Crown. It had no formal legal status or powers, but relied on the Ministers to give advice, and exercise powers, consistently with Cabinet's decisions.

3. Cabinet developed collective responsibility as a means of negotiating with the Crown. It was easy for the monarch to find new Ministers, but difficult to find a whole new Ministry. If refusing advice meant the whole Cabinet would resign, this made it more difficult to refuse.

4. Likewise, as the power of the Parliament grew, collective responsibility became a weapon the Ministry could use against Parliament. If no alternative Ministry with confidence could be formed easily, Ministers could rely on the threat of the Cabinet resigning to stay in office.

5. Like Cabinet, National Cabinet is composed of separate officeholders (the PM and Premiers) responsible for their own powers. It is a committee, with no legal power to control the exercise by separate Governments of their powers. It relies on Premiers to implement decisions.

6. Like Cabinet, collective responsibility is a political weapon that National Cabinet can use to make it more difficult for the electorate (not the monarch!) to hold them individually responsible for decisions taken in response to COVID-19. "It's Cabinet's decision, not mine!"

7. This weapon has been the key advantage of the National Cabinet in selling the COVID-19 response to the public. As can be seen in the areas where States have taken different approaches, difference is more difficult to justify, and requires nuanced messaging to explain.

8. National Cabinet, as a cross-party body, has also been extremely effective in neutering Oppositions. Opposition Leaders have struggled to find a way to criticise decisions made by a body that comprises, and is defended by, senior elected figures of their own party.

9. A key difference between the traditional and National Cabinets, as many have pointed out, is National Cabinet is not responsible to any Parliament. But the PM and Premiers remain responsible to their own Parliaments, much like Ministers of Departments in the pre-Cabinet era.

10. Many have labelled the National Cabinet a re-badged COAG. But this misses the key difference, collective responsibility amongst the PM and Premiers for the National Cabinet approach. COAG, and the Premiers' Conference before it, has always been a political battleground.

11. The big question, will National Cabinet outlast COVID-10? I think it's unlikely. The benefit to the PM/Premiers of collective responsibility in this extreme scenario is ordinarily outweighed by the political benefit of owning COAG's achievements, and bemoaning its failures.

(See, for example, the question of school re-openings, which National Cabinet has left to the States to decide and which has ignited debate and criticism across State and Federal politicians.)

12. National Cabinet may have a role to play where there is consensus amongst the PM and Premiers on measures which are politically unpalatable, but outside of a crisis, those scenarios will be rare. I predict that, post-COVID-19, we will be back to business-as-usual.