A minority led by De Valera brought about Irish civil war

Given that the Dáil and the Irish people voted to accept the treaty, I would argue that the civil war came about specifically because a minority, led by Éamon de Valera, refused to accept the vote of their own parliament (which they fought to establish) with de Valera declaring that the majority had no right to do wrong.

So much for a new Irish parliament for the Irish people.

Éamonn also writes that if negotiations between de Valera and James Craig had persevered, a federal Ireland with an autonomous Ulster province might have resulted.

My understanding is that the two men did not see eye to eye at all, they only had one meeting described by Craig as having no practical benefit with de Valera spending too much time listing centuries of Irish grievances.

Thomas Stewart, Belfast BT4