The essay reports on the methodology and activities of a current project of the American Institute of Physics's (AIP) Center for History of Physics to enlarge the international component of its International Catalog of Sources for History of Physics and Allied Sciences (ICOS). The ICOS project identifies an institution in each foreign country to survey its repositories and send information on the location and content of collections to the AIP for cataloging, indexing, and sharing with RLIN-AMC. Comments on the impact of political upheavals and on other problems and successes are included.