There are two pieces of evidence that Kevin Rudd’s shock Papua New Guinea agreement on asylum resettlement has achieved its initial political goal. Polls now confirm the announcement has dramatically narrowed, possibly even eliminated, the once vast gap between the parties in voter perceptions of their ability to handle the asylum seeker issue. And Tony Abbott has now produced not one but two hastily cobbled-together announcements on the subject in an effort to play catch-up: last week’s bizarre announcement of a new chief-of-service level general outside the military chain of command to do … well, something, it’s unclear what, that wasn’t being done now by the ADF; and now a claim that he’ll build a tent city on Nauru to house asylum seekers.

They’re both the work of a party clearly rattled that Rudd has massively altered the framing of an issue on which it has so effortlessly led for so long.

Despite the policy and rhetorical inflation from both sides, the major parties have essentially the same approach to asylum seekers: to adopt such punitive policies toward them that they are deterred from risking a boat journey to Australia. There may be differences in nuance on how draconian the two sides’ policies are, but they are nuances only.

The long-term policy problem is whether the deterrent-based strategy can work at all. Trying to prevent people from risking drowning is a worthy goal, however much it may be denounced by asylum seeker advocates. But what happens if the government — whether a Rudd government or an Abbott government — discovers that it can’t stop the boats, no matter how draconian it may be?