And it was about getting a republican anti-internment rally through the city's streets without the running battles and bleeding of last year.
There was a loyalist protest on Royal Avenue but, this time, the police were there in greater numbers and had control of all nearby streets and junctions. And, in this operation, the police mixed officers in high-visibility jackets with many more in riot gear.
At times, you could hear their dogs barking in the vans and, at several points, water cannon were parked up at visible points just in case they were needed.
This wasn't your normal Sunday – nor was it a picture that will be used as an advertisement for a city at peace with itself in this year the 20th anniversaries of the ceasefires.
Yesterday, it was after 2pm when the parade approached Royal Avenue and the critical minutes were those as it passed the loyalist protest.
Only then could the city begin to breathe again and, as the police operation was lifted, so the buskers sang and the shoppers shopped.
"At least no serious injuries or damage," a senior PSNI source said. "Sorry to have such a low threshold for getting positive about these things, but after last year this is an okay result.
"It could have been another complete mess."
It wasn't the "mess" of last year, but it was ugly – ugly in terms of how these big security operations look, the picture even more miserable as relentlessly the rain fell.
This was another of those moments when the events of many decades ago just trampled through the present.
In the history of this place, internment dates back to the 1970s – we were back many years before the ceasefires and subsequent political agreements, and still marching messes up the city centre.
A taxi driver raged about the cost to the economy and asked had no one the courage – not his term – to stand up and call for a ban on all marching in the heart of the city.
Budgets are being squeezed and still huge amounts are being spent on these operations – money that ran down the city's drains in those several hours yesterday.
And, yet in the current climate, there is no alternative to such policing.
The Secretary of State is still considering what to do to address the parade standoff in north Belfast, where at the weekend PUP leader Billy Hutchinson predicted further political moves soon in the "graduated response".
And, then there's the bigger question of marching in the city centre.
In the absence of answers, the police are left holding the different lines.