the third Northern Ireland Executive, the same political relationship existed between Robinson and McGuinness as existed formerly between Paisley and McGuinness. After Robinson resigned as First Minister on 11 January 2016, he was replaced by Arlene Foster. Upon McGuinness's resignation on 9 January 2017, the devolved government in Stormont collapsed, as the Agreement demands when no new leader is appointed. An election was called by Secretary of State for Northern Ireland James Brokenshire, whereby the DUP and Sinn Féin were returned as the largest parties, and so began a countdown of talks between both leaders before devolved government could be restored. In January 2020, the Executive was re-established. Comparison to the Sunningdale Agreement Seamus Mallon referred to the Agreement as "Sunningdale for slow learners", which suggests that it was nothing more than what was on offer in the Sunningdale Agreement of 1973. This assertion has been criticised by political scientists like Richard Wilford and Stefan Wolff. The former stated that "there are ... significant differences between them [Sunningdale and Belfast], both in terms of content and the circumstances surrounding their negotiation, implementation, and operation". The main issues omitted by Sunningdale and addressed by the Belfast Agreement are the principle of self-determination, the recognition of both national identities, British-Irish intergovernmental cooperation and the legal procedures to make power-sharing mandatory, such as the cross-community vote and the D'Hondt system to appoint ministers to the executive. Former IRA member and journalist Tommy McKearney says that the main difference is the intention of the British government to broker a comprehensive deal by including the IRA and the most uncompromising unionists. Regarding the right to self-determination, two qualifications are noted by the legal writer Austen Morgan. Firstly, the cession of territory from one state to another state has to be by international agreement between the UK and Irish governments. Secondly, the people of Northern Ireland can no longer bring about a united Ireland on their own; they need not only the Irish government but the people of their neighbouring state, Ireland, to also endorse unity. Morgan also pointed out that, unlike the Ireland Act 1949 and the Northern Ireland Constitution Act 1973, devised under Sunningdale, the 1998 agreement and the consequent British legislation did expressly foresee the possibility of a united Ireland. As well as the number of signatories, Stefan Wolff identifies the following similarities and differences between the issues addressed in the two agreements: