As Chairman of the Research Commission on National Security, Arita participated in the debate over the Treaty on the Non-Proliferation of Nuclear Weapons.

However, in the case of a military threat, Arita stressed the importance of US-Japan cooperation and the strength of the Japan Self-Defense Force.

Upon his calling to the cabinet, then, Arita declined service in his position, citing the lack of representation for Fukuda supporters within the government.

This was before the change in the Defense Agency's perception of China to an indirect threat in early 1970 under Prime Minister Yasuhiro Nakasone.

[4] Arita was also the writer of the first Defense white paper in Japan in 1970 - his original draft argued for increased defense capability if there was ever a "delay" in assistance from the US in case of an invasion, but the final draft saw Arita back down on this, as he called for "autonomous defence capability" only, a controversial move.