[6] Twomey opposed the Anglo-Irish Treaty of December 1921 and was critical of the tactics adopted by the anti-Treaty forces - the occupation of the principal seat of justice in Ireland the Four Courts.

[7] He was influenced by Oscar Traynor's opinion that an attack by the newly formed Irish National Army to end the occupation of the Four Courts would destroy the Republic.

[8] The subsequent destruction of the Four Courts showed government leadership that it was out of touch with the level of opposition to the treaty and also the awesome power of artillery.

[13] The pact was originally approved by Frank Aiken, who left soon after, before being succeeded by Cooney and Twomey who kept up the secret espionage relationship.

"[13] Nevertheless, London-based IRA spymaster Seán MacBride passed specifications of "submarine detection sonar and aeroplane engines for bombers, military journals and manuals, and gas masks"[13] to the USSR through Berlin-based GRU operative Walter Krivitsky, whom ciphered IRA communications referred to only by the code name "James".

[14] Meanwhile, the IRA's main spymaster in America "Mr. Jones", whom historians Tom Mahon and James J. Gillogly have identified as Daniel "Sandow" O'Donovan,[15] passed "reports of the army’s chemical weapons service, state-of-the-art gas masks, machine-gun and aeroplane engine specifications, and reports from the navy, air service and army" to the Soviet GRU.

Twomey considered himself a moderate, had a deep sense of history, and the belief that Ireland had the resources to provide a good living for all of its people.

However, Saor Eire quickly found itself under attack from both Cumann na nGaedheal and by the Catholic Church in Ireland for being a Pro-Soviet organisation, with the IRA painted as guilty by association.

Simultaneously, the Cumann na nGaedhael government gave itself emergency powers and began arresting IRA members.

[17] In February 1932, Cumann na nGaedhael called an early election, hoping to catch both the IRA and Fianna Fáil on the backfoot.

To the surprise of many, Cumann na nGaedhael chose to respect the result of the vote and stood aside to let Fianna Fáil into power.

During his period of imprisonment his family depended heavily on money sent to them by Joseph McGarrity of Clan na Gael, a US-based IRA fundraising organisation.

While he did not take an active role in politics after the 1940s, he did speak at a number of republican commemorations, most notably at the restoration of Wolfe Tone's grave at Bodenstown in 1971.

[24] Twomey's papers from his period as IRA chief of staff, consisting of 28 boxes, are now kept at the Archives Department of University College Dublin.