The struggle is over who gets to be the next president, a post reserved for a Christian under Lebanon’s Constitution, and which must be filled by the end of November. But the larger question — one that is prompting rival Christian factions to threaten war — is whether Lebanese Christians must accept their minority status and get along with the Muslim majority (the choice of the popular Gen. Michel Aoun) or whether Christians should insist on special privileges no matter what their share of the population (the position of veteran civil war factions like the Phalange and the Lebanese Forces).

The government dedicated an extraordinary cabinet session in September to reports that Christian factions had opened militia training camps in the mountains. The police have arrested two groups of Christians allegedly linked to General Aoun’s party — the most recent on Thursday — and accused them of illegal weapons training. One group said that they were on a picnic and the other that they were “playing.” General Aoun said his followers keep only “personal weapons,” like most Lebanese.

Mr. Abbas, the man in the tattoo parlor, used to work as a luxury hotel receptionist. In the last six months, in anticipation of a coming struggle, he has moved his family out of Beirut to the mountains, and has joined the militant wing of the Lebanese Forces, a pro-government party.

Government leaders say they worry that within days of a renewed conflict, heavy weapons could flow to rival Christian factions from Israel, France, Syria, or even the United States.