In one of the Einstein-Szilard letters, it is mentioned that Leo Szilard has submitted a paper with details of setting up a uranium chain reaction, which is due to be published by the journal Physics Review. Einstein suggests that it might be necessary to delay publication of this paper. In the context of the issues discussed in the letters, especially as regards concern about Germany, what might be the reasoning behind wanting to delay, or ban the publication of Szilard's paper?