I read reports about the Particle Physics Project Prioritization Panel (P5) report, and have skimmed the P5 report itself. I do think that the future of particle physics lies with neutrino physics, but I am sure I am biased.
One thing I am certain of is that future big physics (or big science) should be done under the formality of international agreements as a fundamentally international collaboration. This is not only that such big projects require more funding than any nation desires to provide and requires more expertise than any one nation can provide, but because of the nature of big physics and the nature modern (especially democratic) governments.
The nature of big physics is that projects take 15-60 years from initial concept to completion. This is a large time scale, is a significant fraction of a human life, and is at least greater than one career cycle for the scientists (time spent between a scientist starting the PhD and acquiring a tenure-tracked position after a postdoc). During this time, funding and the interest of scientists (which depends on the prospect of future funding in addition to actual scientific interest) must be maintained above a minimum or the project is a complete failure. There are additional thresholds at which if the interest and funding drops below for even a short time (a year or two) results in significant deficiencies in the program. These deficiencies basically mean that promised results become impossible and significant effort and funding is wasted.
The nature of modern (democratic) governments is that they are made up of politicians whose primary concerns are politics and the next election. As such their vision is only of the next 2, 4, 5, or 8 years. This means that a big physics project is many multiples of a political cycle. Due to the changes of politics (and even the changes in the global situation) there will be times of austerity as well as times of stimulus. The success of long term projects or even the long term efficiency of the political efforts are not of primary concern to governments.
Both times of austerity and stimulus can be damaging for the success of big physics. Times of stimulus might cause a program to be initiated which is too large. Then even normal times can mean that the support of the project is below what is necessary to achieve the desired results and possibly some other project would be a better use of the resources. Times of of austerity are an obvious problem point, here the the support of the project might even drop below the minimum amount and the project becomes a complete waste of resources and effort.
One possible solution is to make projects international. European Organization for Nuclear Research (CERN) provides a template for how to do this. CERN is set up by treaty between the member states, resulting in an organization whose purpose it is to insure the long term success of the big physics project. This results in states being encouraged by international law to contribute the necessary amount for the success of the project and if some state (due to politics or necessity) does not contribute the necessary amount, the rest of the member states can contribute what is necessary for the successful completion of the project. This structure not only allows bigger projects to be attempted than any one state can realize, and enhances international collaboration, but also protects against the vagaries of modern (democratic) governments.
This is advantageous even for the biggest and richest countries like the United States. I know I was not alone in imagining worse case scenarios for some spectacular physics programs during the recent government shutdown in the United States.
It is the CERN model that researchers in the Latin American countries of Mexico, Argentina, Chile, and Brazil have followed in proposing a new underground laboratory in the southern hemisphere. Here in Latin America, the needed expertise for leading research obviously requires an international approach. However, following the CERN model for funding also allows long term scientific projects to not be at the mercy of short term democratic vagaries.
Further reading on P5:
http://news.sciencemag.org/physics/2014/05/new-plan-u.s.-particle-physics-go-international
http://www.symmetrymagazine.org/article/may-2014/proposed-plan-for-the-future-of-us-particle-physics
http://www.usparticlephysics.org/p5/
Further reading on ANDES:
http://andeslab.org/
Further reading on CERN:
http://council.web.cern.ch/council/en/governance/Convention.html
