Belfast, Northern Ireland
As Britain's general election approaches, the main question in Northern Ireland, which holds 17 seats in the British Parliament, is the existence of Ulster itself.
Voters are divided along religious lines: Protestants are expected to choose mainly unionists, who favor retaining the link with Britain; Roman Catholics will choose Irish nationalists, who want a united Ireland.
Within the ranks of unionists and nationalists, however, two key contests are being fought. On the nationalist side, the Social Democratic and Labour Party (SDLP) is battling with the Provisional Sinn Fein, the political wing of the outlawed Irish Republican Army (IRA), for a half-million Catholic votes.
The 1 million Protestant votes will be divided among the Official Unionist Party, the Rev. Ian Paisley's Democratic Unionists, and the moderate Alliance Party.
Catholic voters must choose between the constitutional politics of the SDLP and the more violent methods of Sinn Fein.
Sinn Fein's aim is to drive the British out of the north and to change Ireland into a socialist republic. The party's stronghold is among unemployed Catholic young people.
The Catholic Church has weighed in heavily against Sinn Fein. But the hard-core frustration vote from youth could be significant.
The outcome in the SDLP-Sinn Fein struggle could measure public acceptance of violence. In the assembly elections last October, Sinn Fein took 10.1 percent of the nationalist vote to the SDLP's 18.8 percent. If Sinn Fein manages to narrow that gap this time, it will be taken as an endorsement of violence and a blow to the SDLP's constitutional politics.
Sinn Fein will run head-on with the SDLP in 14 of the 17 constituencies. The SDLP is expected to take two to four of the seats, including that of SDLP leader John Hume. Sinn Fein is expected to take at least one seat, with its vice-president, Gerry Adams, consolidating his power base in west Belfast.
Across the religious divide, the mainly Protestant unionists have failed to consolidate in those areas where the Protestant vote is limited. Democratic Unionist leader Paisley and Official Unionist leader James Molyneaux cobbled together an agreement to field only one unionist in three areas where the Protestant vote could be split - giving nationalists an edge - but not on three others.
The breaches between unionist parties have widened over views on the Northern Ireland Assembly. Democratic Unionists want the Assembly to work. Some Official Unionists want it to work, if it is changed to suit them; others want integration with Britain.
Many observers will be watching to see whether the unionists can agree among themselves. If they cannot agree, observers wonder whether it would be possible for them to work with Catholic nationalists.