Getting a bit ahead of myself, I'd like to talk about an article that CSO won't be publishing until next month. As part of our continuing series of articles on challenges facing the Department of Homeland Security, this story concerns the economic puzzle of how to fund the hardening of the critical infrastructure. Among the insights conveyed by sources in Senior Editor Sarah D. Scalet's May feature is this quite simple one: The economic models for building, maintaining and securing the current infrastructures did not contemplate terrorism. As a result, debate about what to do now and in the future often stubs its toe on the past.The electric power grid wasn't built to withstand terrorism. It wasas was shown last summerbarely built to withstand slightly elevated levels of human error and malfeasance. While it would be a fairly straightforward matter of long-term investment to rebuild the grid to be a more efficient, more resilient architecture, the presence of terrorism in the world adds urgency that fundamentally changes the problem, both in nature and degree. The more recent example of the Madrid commuter rail bombings presents a similar challenge. Unlike the air travel infrastructure, which had the benefit of already being a closed (or, at worst, a closable) system, the rail infrastructure doesn't so easily lend itself to more stringent security.But Scalet's story is not so much about how best to fix what's broken as it is about who should be made to pay for the repairs. Resolution of that question will either compromise or enhance the goal of achieving improved security through a partnership between government and the private sector. This difficult controversy impinges upon the task of remediating vulnerable infrastructures. In fact, it may turn out that the debate over how to fix the assorted vulnerabilities is forced to take a backseat to the debate about who should pay to fix the mess and who therefore (by virtue of signing the checks) gets to decide which solutions take precedence.It would be greatand something of a miracleif the public-private partnership model could find its stride quickly, producing the requisite levels of trust, efficiency and strategic wisdom. The abundant skepticism about the model, though, tends to be well-founded, considering all of the narrow but perfectly natural special interests that stand in the way of truly original thought and action. If the stakes were lower, it would be easier to fend off despair.Interestingly, you don't necessarily have to wait until the May issue of CSO to find out more. CSO is hosting a conference April 18-20 at the La Costa Resort and Spa in Carlsbad, Calif. I have the pleasure of moderating a panel on the topic of public-private partnership. (It appears the panel will include some of the sources from our article.) We would be happy to see you there. We can all drop some Prozac together.