This article reports the results of an econometric evaluation of the effects of Plan Colombia, the largest US aid package ever received by a country in the western hemisphere. We assess how the aerial spraying of illegal crops affects both the size of the land cultivated with coca bushes as well as the dynamics of localized violence in the context of Colombia’s armed conflict. In particular, we...

Many malicious and fraudulent endeavors on the web exhibit characteristics of asymmetric conflict and guerrilla warfare. Defenders work continuously to detect and take down malicious websites, while attackers respond by resisting takedowns, evading detection, or creating large numbers of new sites. This is reminiscent of the arcade game of whack-a-mole – the faster the moles pop in and out of t...

BACKGROUND AND AIMS A phalanx growth form enables clonal plants to make better use of resource-rich patches, whereas a guerrilla growth form provides them with opportunities to escape from resource-poor sites. Leymus secalinus produces both spreading (guerrilla form) and clumping ramets (phalanx form). Here, the hypothesis that a trade-off between the two growth forms in L. secalinus exists und...

Terrorism is the greatest threat to national security and cannot be defeated by conventional military force alone. In critical areas such as Iraq, Afghanistan and Turkey, regular forces cannot reach these hostile/terrorist groups, the instigators of terrorism. These groups have a clear understanding of the relative ineffectiveness of counter-guerrilla operations and rely on guerrilla warfare to...