“Ten-flag Tony”, Prime Minister Abbott was dubbed, as the number of flags behind him at his ever-proliferating number of national security announcements grew and grew; journalists began making bets on how many would be wheeled in ahead of every media conference. The urbane Malcolm Turnbull was better than that, of course — the man who as a minister dismissed claims from his colleagues George Brandis and Julie Bishop that Islamic State was an “existential threat”, the man who seemed too worldly, too self-aware, to rely on crass jingoism to bolster his flailing government.

Yesterday, though, Turnbull out-flagged Abbott, comprehensively. Instead of pole after pole of flags, neatly arrayed behind him, Turnbull announced that the government would be making it easier to call out the military for domestic terrorism incidents at what looked for all the world like a Call of Duty convention, with gas-masked soldiers, an assortment of rifles and other military paraphernalia, including an assault vessel — any terrorist incidents on our waterways, presumably, would be dealt with vigorously.

It was absurdly over the top, childishly so; Abbott’s flags looked subtle in comparison.

But shortly thereafter there was a leak from the government: Turnbull was to hand senior conservative Peter Dutton the prize of a homeland security portfolio, over the objections of Attorney-General George Brandis, Foreign Minister Julie Bishop, Defence Minister Marise Payne and Justice Minister Michael Keenan.

And this morning, Turnbull confirmed it: Dutton would lead a department of home affairs, comprising immigration, border protection, the Australian Federal Police and the domestic intelligence organisation ASIO, as well smaller crime-related agencies like the Australian Crime Intelligence Commission and AUSTRAC.

There’s no specific reason for the restructuring: it hadn’t been recommended by the review of the intelligence community just completed by Michael L’Estrange and Stephen Merchant; for years, governments have insisted Australia’s counter-terrorism capacity was the world’s finest; a homeland security department, in fact, was a Labor idea for much of the 2000s, routinely dismissed as unnecessary by the Coalition both in government under John Howard and by Turnbull himself when he led the Coalition in opposition. In announcing the body, Turnbull repeatedly cited the UK Home Office as a mode, despite the failure of that structure to prevent multiple serious terrorist attacks in the UK.

[EXCLUSIVE: leaked cabinet papers detail plan to make Dutton a super-duper minister with lasers]

The primary reasons are twofold. Turnbull is eager to keep the focus on national security — from his war on maths, banging the drum on cybersecurity and the ADF announcement — under the impression it will bolster his political stocks, both internally and with the electorate. Tony Abbott believed the same, ratcheting hysteria over terrorism to ever higher levels and even accusing the opposition of “rolling out a red carpet for terrorists”. Abbott turned out to be wrong; Turnbull so far has turned out to be wrong, as well, but who knows into the future?

The other, more important reason is that Turnbull’s position is desperately weak and he is in no position to deny the most powerful conservative in his cabinet what he wants: a mega-portfolio to rival defence for money, hardware, intelligence and powers and profile.

Dutton’s win is deeply humiliating for Attorney-General George Brandis, who has lost two of the most important security agencies. He’s been given a fig leaf for his humiliation — the shift of the Inspector-General of Intelligence and Security, the Ombudsman and the Office of the Independent National Security Legislation Monitor. Brandis, who has been a serial bungler as Attorney-General, had already lost oversight of counter-terrorism to Justice Minister Michael Keenan, who’ll be moving to the new portfolio under Dutton. But this is as comprehensive a gutting as possible without sacking him.

This is a crippled Prime Minister, desperately clinging to national security as a prop for his authority, unable to resist the demands of the man who is seen as a likely successor to him, who will now be given an even higher profile role in which to burnish his reputation with the electorate and, more importantly, his own party.