He was especially important in dealing with Stalin's proposal for the Finno-Soviet Treaty in the late winter of 1948.
He was Secretary General of the Finnish Negotiation Delegation in Moscow in March–April 1948, which was considering the Finno-Soviet Treaty.His brother Yrjö Suontausta was a member of the Supreme Court since 1947 and a Member of parliament from the National Progressive Party from 1945 to 1947.