Although precise details of US space-based Sigint satellites launched after 1990 remain obscure, it is apparent from observation of the relevant ground centres that collection systems have expanded rather than contracted. [...] The satellites and their processing facilities are exceptionally costly (of the order of $1 billion US each). In 1998, the US National Reconnaissance Office (NRO) announced plans to combine the three separate classes of Sigint satellites into an Integrated Overhead Sigint Architecture (IOSA) in order to " improve Sigint performance and avoid costs by consolidating systems, utilising ... new satellite and data processing technologies". It follows that, within constraints imposed by budgetary limitation and tasking priorities, the United States can if it chooses direct space collection systems to intercept mobile communications signals and microwave city-to-city traffic anywhere on the planet [emphasis added]. The geographical and processing difficulties of collecting messages simultaneously from all parts of the globe suggest strongly that the tasking of these satellites will be directed towards the highest priority national and military targets. Thus, although European communications passing on inter-city microwave routes can be collected, it is likely that they are normally ignored. But it is very highly probable that communications to or from Europe and which pass through the microwave communications networks of Middle Eastern states are collected and processed.