Adriana Minor's new work uses the career of Manuel Sandoval Vallarta to explore the ways in which the rise in importance of the hard sciences, and especially physics, to nation-states served both to create and constrain opportunities for transnationalism from World War I to World War II.

Prior to reading this book I did not know who Sandoval Vallarta was. I did, however, know the names, career trajectories, and accomplishments of many of the leading transnational scientists who either originated in the United States but did their doctoral work in Europe (such as Robert Oppenheimer), or were born in Europe and came to the United States (perhaps most famously Albert Einstein and Wernher von Braun). Minor notes that this ignorance of the impact of Latin American scientists in the United States is not only common, but was also part and parcel of systemic choices made by US officials, thus underlining both the importance of and need for her work.

Minor begins her book by highlighting the renown and memorialization that Sandoval Vallarta, a physicist who specialized in the study of cosmic rays, received in Mexico, even as his contributions were largely forgotten in the United States. In Mexico, he was “a heroic figure whose relevance is indisputable,” while in the United States he was a marginal figure whose importance was confined to the early history of MIT and quantum mechanics (22). Adopting an approach that understands hemispheric relations as cultural encounters, Minor traces Sandoval Vallarta's career from 1917 to 1942, years that he was constantly in movement, initially between the United States and Mexico but eventually between the United States and much of Latin America, as he took on the role of an ambassador for the advancement of science in the region.

Sandoval Vallarta arrived in the United States to study at MIT in the midst of the Mexican Revolution, just as the United States was mobilizing to enter World War I. This mobilization included aligning the educational training and research at MIT with the war needs of the United States. Sandoval Vallarta studied at MIT until 1924, when he earned his doctorate, and then stayed on as a faculty member until 1942, when he returned to Mexico permanently. He never became a US citizen, though it is clear that this was an option open to him. His non-citizenship, an intentional choice, says much about why he is not remembered better. Even as an elite, it often hampered his ability to return to the United States from Mexico and undermined his social status among his American scientific peers at MIT, because they did not understand why he had passport and visa issues on a regular basis, and because they viewed him as not being totally committed to the Allied cause. On the other hand, the fact that his peers were willing to work with scientists who had worked on behalf of the Nazi regime says much about political and cultural understandings of the time.

Sandoval Vallarta took on a leading role in collaboration with Arthur Compton, the winner of the Nobel Prize in Physics in 1927, in establishing a network of stations to study cosmic rays in the 1930s, including the Observatorio Astronómico Nacional in Teoloyucan, Mexico. This work led to his leadership of the Committee on Inter-American Scientific Publication (CIASP), a program of the US Office of the Coordination of Inter-American Affairs (OCIAA) that successfully sought to tie Latin American scientists more closely to the United States. His cultural diplomacy, part of the US Good Neighbor policy, helped Latin American scientists get their works published in US scientific journals (in lieu of their publication in similar European or Japanese journals).

In spite of his work on behalf of MIT, the United States, and the scientific community, Sandoval Vallarta was removed from his CIASP work and ordered to return to the classroom to teach, a slight that he rightly viewed as resulting from his Mexican citizenship. Sandoval Vallarta declined and stayed on in Mexico to work on behalf of the country of his birth.

Had Sandoval Vallarta been allowed to continue his CIASP work or to contribute to the war related research being carried out at MIT, he might have escaped the obscurity into which he fell in the United States. Minor's work is one excellent step in changing this direction.