A new constitutional order was unveiled in Ireland in 1937, but proscription was soon revived and has since endured. In this and other respects, the current Constitution (Bunreacht na hÉireann) bears pronounced resonances with past arrangements, including the establishment of special courts and the declaration of a state of emergency in a time of war or armed rebellion. At the same time, compared to its 1922 predecessor, fundamental individual rights are accorded greater prominence and enforceability, and less malleability is allowed. However, the 1937 Constitution was soon sorely tested by the combined destabilising effects of, first, the international turmoil caused by mounting German aggression and, second, the IRA’s wish to exploit this instability, through its ‘S’ Plan at the end of 1938, by declaring that its Army Council represented the legitimate government of Ireland and by issuing an ultimatum to the British government to withdraw from Northern Ireland. The IRA followed up these declarations with a campaign of bombings in England in early 1939 and with collusion with the German authorities. Both actions put in jeopardy the Irish Government’s policy of international neutrality. As a result of these dire circumstances, and even before a national emergency was declared on the 3 September 1939, the Irish Government decided to revive many of the old coercive powers, including proscription. Consequently, the Offences Against the State Act was passed on the 14 June 1939. Some contend that the 1939 Act embodied ‘important changes, with most of these veering in a somewhat more liberal direction’. In reality, there were more echoes than cleavages from the past. The relevant details of the 1939 Act are examined in this chapter. The analysis will consider: the powers to proscribe and the selection of impugned organisations; and the consequences of proscription, mainly involving criminal offences. In both aspects, the normative performance in terms of constitutionality, oversight and accountability will be assessed