Astrophysics and Cosmology: International Partnerships

Most large projects in astrophysics and cosmology are international. This raises many challenges including: \begin{itemize} \item{Aligning the sequence of: proposal, planning, selection, funding, construction, deployment, operation, data mining in different countries} \item{Managing to minimize cost growth through reconciling different practices} \item{Communicating at all levels to ensure a successful outcome} \item{Stabilizing long term career opportunities.} \end{itemize} There has been considerable progress in confronting these challenges. Lessons learned from past collaborations are influencing current facilities but much remains to be done if we are to optimize the scientific and public return on the expenditure of financial and human resources.