DUBLIN — Northern Ireland was thrown into turmoil this week when the province’s pro-British first minister resigned from the executive branch, taking his party’s ministers with him and leaving the government unable to function. Here are answers to some questions about the developments:

Q. What is the status of the government?

A. The government, in which pro-British unionists and Irish republicans share power by official mandate, cannot conduct any business without the participation of either of the two largest parties, so it is hanging by a thread. It has not officially collapsed, however. When Peter Robinson, the first minister and leader of the majority Democratic Unionist Party, resigned, he appointed one of his colleagues as acting first minister to stay behind and retain a toehold in the government.

Q. What happens next?

A. Mr. Robinson said Friday that he would renominate his ministerial team next Friday, and then immediately have all but one resign again — thus prolonging the limbo.

Q. What is behind the current political crisis?

A. On Aug. 12, a former Irish Republican Army activist, Kevin McGuigan, was murdered in Belfast, and the police blamed I.R.A. members. The official assertion that the organization was still in existence upset the unionists because their main republican partner in the Northern Ireland government is the Sinn Fein party, the former political wing of the I.R.A. Sinn Fein has long insisted that the I.R.A. is defunct; many of the Sinn Fein lawmakers are themselves former I.R.A. members.

In remarks on BBC radio on Aug. 27, Jeffrey Donaldson, a Democratic Unionist member of the British Parliament, threatened unilateral action by his party if the assembly did not support the expulsion of Sinn Fein from the government. “If that means that we have a period in Northern Ireland where we don’t have a government until we resolve and sort out these issues,” he said, “then so be it.”