Why Russia and China Have Not Formed an Anti-American Alliance

"Why Russia and China Have Not Formed an Anti-American Alliance," Naval War College Review, 56: 4 (Autumn 2003), pp. 39-61

Terrorism in Eurasia: Enhancing the Multilateral Response

"Terrorism in Eurasia: Enhancing the Multilateral Response," The China and Eurasia Forum Quarterly 4: 2 (May 2006), pp. 11-18

Civil Society and Philanthropy Under Putin

"Civil Society and Philanthropy Under Putin," The International Journal of Not-for-Profit Law 8: 3 (May 2006

Let my people go (home) to Spain: a genealogical model of Jewish identities since 1492

The Spanish government recently announced an official fast-track path to citizenship for any individual who is Jewish and whose ancestors were expelled from Spain during the inquisition-related dislocation of Spanish Jews in 1492. It would seem that this policy targets a small subset of the global Jewish population, i.e., restricted to individuals who retain cultural practices associated with ancestral origins in Spain. However, the central contribution of this manuscript is to demonstrate how and why the policy is far more likely to apply to a very large fraction (i.e., the vast majority) of Jews. This claim is supported using a series of genealogical models that include transmissable "identities" and preferential intra-group mating. Model analysis reveals that even when intra-group mating is strong and even if only a small subset of a present-day population retains cultural practices typically associated with that of an ancestral group, it is highly likely that nearly all members of that population have direct geneaological links to that ancestral group, given sufficient number of generations have elapsed. The basis for this conclusion is that not having a link to an ancestral group must be a property of all of an individual's ancestors, the probability of which declines (nearly) superexponentially with each successive generation. These findings highlight unexpected incongruities induced by genealogical dynamics between present-day and ancestral identities.Comment: 6 page, 4 figure

The Limits of U.S.-China Military Cooperation: Lessons from 1995-1999

"The Limits of U.S.-China Military Cooperation: Lessons from 1995-1999" (with Kurt Campbell) The Washington Quarterly 29: 1 (Winter 2005), pp. 169-186

Packing-limited growth of irregular objects

We study growth limited by packing for irregular objects in two dimensions. We generate packings by seeding objects randomly in time and space and allowing each object to grow until it collides with another object. The objects we consider allow us to investigate the separate effects of anisotropy and non-unit aspect ratio. By means of a connection to the decay of pore-space volume, we measure power law exponents for the object size distribution. We carry out a scaling analysis, showing that it provides an upper bound for the size distribution exponent. We find that while the details of the growth mechanism are irrelevant, the exponent is strongly shape dependent. Potential applications lie in ecological and biological environments where sessile organisms compete for limited space as they grow.Comment: 6 pages, 4 figures, 1 table, revtex