As an ex-police officer, the Home Affairs Minister designate, Peter Dutton, is well aware that public trust will be critical to the success of the coalition's home affairs policy. If the media response to Prime Minister Malcolm Turnbull's home affairs announcement is anything to go by, Australians have concerns over this new arrangement. A point that doesn't bode particularly well for its implementation.

While this weekend's counter terrorism operations in Sydney will be a reminder to all Australians that the terrorism threat is real, it is unlikely to have garnered much additional trust in the government's planned changes.

Australia's police officers know that public trust is critical to maintaining law and order;they're fixed on maintaining community trust. It's trust that results in community cooperation with our national security agencies.

The UK government's Home Office is the model for Dutton's new super department. But, that organisation hasn't fared well on the trust front (see here, here and here).

In 2008, the British Home Office abandoned the use of public confidence as a performance measure. The global financial crisis at the time forced the then-Prime Minister David Cameron to embark on a harsh austerity program.

Cameron's drastic cuts to domestic security expenditure negatively impacted on public confidence in the Home Office. It also undermined trust between the overstretched operational agencies and the Home Office.

The tough nut for Dutton to crack will be building the legitimacy of his department, and its portfolio agencies, in the face of strong arguments against its establishment.

The United States' experience with the Department of Home Land Security (DHS) should also stand as a warning of how bad trust deficits can get. Following the September 11 terror attacks, the then-newly established DHS directed that the U.S. Customs and Border Protection (CBP) rapidly expand in size.

In response, CBP lowered many of its recruitment standards, including security vetting. In the years that have passed, over 140 CBP agents have been convicted of offences including corruption and illegal use of force.

Today, communities along the U.S. Southern Border simply don't trust CBP, which impacts on the agency's day to day operations and border security.

Over the coming months, Dutton will need to build the public's trust in the government's Home Affairs super department. He must convince Australians that the Commonwealth's new domestic security arrangements are lawful and legitimate.

The public needs to be convinced that Home Affair's agencies, from ASIO, the AFP and the Australian Border Force, will use their powers in a lawful, fair, transparent and politically neutral manner.

These agencies already go to great lengths to ensure their compliance with constitutional, legislative and ethical responsibilities. But Australians are demanding greater transparency in domestic security decision making.

Neither the secrecy provisions of Operation Sovereign Borders nor 'trust us' arguments will cut the mustard this time.

Turnbull understands these concerns. He's announced that his government would reinforce the role of the Attorney-General as the minister for oversight and integrity. But, on its own, this won't be enough to restore trust in the new Home Affairs arrangements.

The tough nut for Dutton to crack will be building the legitimacy of his department, and its portfolio agencies, in the face of strong arguments against its establishment. He'll need to convince Australians that our new national security arrangements are the right ones for the country.

For Dutton, there'll be no easy answers. But the Turnbull government should draw upon police experience in building community trust.

First, Home Affairs should promote, across the portfolio, respect for people, be they Australian, or not. Home Affairs agencies ought to demonstrate how they'll focus on doing what's best for the community.

Second, statutory bodies, especially those with policing type powers, should promote how they'll maintain their political independence in operational matters.

Finally, the community need to be afforded the opportunity to contribute to national security strategies, especially those focused on law enforcement.

Dutton knows that the successful implementation of the Home Affairs arrangements will be critical to the government's re-election. There's a lot riding on Dutton being able to bridge a very real public trust deficit with the Turnbull government's new Home Affairs mega Department.