After 1 July 1968, when the NPT had been opened for signature, Brandt brought up the accession question in a letter to the Chancellor, arguing that the “credibility of our détente policy” depended on Germany’s stance toward the NPT, which in his review it should sign by “early autumn." Brandt’s letter mirrored arguments made previously by Georg-F. Duckwitz, who was State Secretary in the Foreign Office.

In a stern letter to the Chancellor Kiesinger, the Minister of Finance Franz Josef Strauß explained that he would “fight against” the NPT. Strauß was chairman of the Bavarian CSU and had served as Minister of Defense between 1956 and 1962. His point was that a decision to accede to the treaty was unthinkable as long as he remained minister in Kiesinger’s cabinet and, hence, with the CSU participating in the ‘grand coalition’. Strauß’ letter also indicated his suspicion of Foreign Minister Willy Brandt and his disposition towards the NPT which Strauß apparently regarded as submissive.