It sounds sort of like an Unintended Consequences story line. From the website:
The year is 2018, seven years after the successful end of an American-led world war on terrorism, but the nation is now faced with an even more horrible prospect: a war against an enemy it can not defeat—itself. In the face of the gathering storm clouds of war, Jeremiah Kincaid, 59, the Republican Speaker of the House, struggles to mediate a growing firestorm of public debate over gun control. On the left is Alexander Webster, 49, the Democratic President, who halfway through his final term, decides to make the elimination of guns from America his legacy. On the right is Edward Morrissey, 61, the Republican Governor of Idaho, who bitterly opposes the President’s position.
Exacerbating the situation, militia seize a gun club built on Federal land in the Bitterroot Mountains of Idaho, which the Park Service had closed. After losing patience with Morrissey’s handling of the problem, Webster sends in Army Rangers, and in the ensuing battle many men die. The militia’s handsome leader, Thomas Porter, 34, escapes. He is a multi-billionaire with a past shrouded in mystery. The massacre on the mountain sets in motion a sequence of events that eventually leads to the secession of Idaho from the Union. As the country falls apart around her, Sarah McGill, 34, a rising television network star, finds herself falling in love with two men; a dashing Army officer, Jake Kincaid, 36, the son of the Speaker of the House, and the enigmatic Thomas Porter; and what makes this drama of the human heart all the more poignant is that Jake and Thomas are long-lost brothers.
And volume two:
Driven by emotion rather than logic, President Webster approves an ill-advised plan to kidnap Governor Morrissey using Army Special Forces. However, the attempt fails, which drives the governments of six other western states to secede and form the Continental States of America with Morrissey as its President. Eventually, President Webster is left with no choice but to declare war on the new confederacy. The brutal civil war that ensues lasts for seven days and involves the most ferocious and devastating tank battles in history. By the time it ends, the blood of over one hundred thousand soldiers has been spilled on the savaged soil of the sorrowed nation.