It's been 160 years. You don't need to keep repeating the propaganda. A bunch of warships and a troop carrier are Not a "resupply mission." They are a deliberate and intentional provocation to trigger a war.
Even though his Secretary of State advised him that it would be war and the world would view it as his fault.
It was *ALL* of his secretaries except one that told Lincoln this would trigger a war. Lincoln knew what he was doing. He needed a war to justify stopping Southern trade with Europe. If he didn't, the money would shift from New York to the South, and the power would have eventually shifted with it.
Davis decided on war.
Lincoln decided on war in his Inaugural address. The confederates naively thought they could negotiate to settle matters. Any result that didn't include New York and Washington DC controlling their entire export income, wasn't going to be accepted.
Lincoln would accept strengthening slavery. He would not accept the loss of control over Southern produced money, or the economic competition for his backers in New York.
It is a resupply mission. Warships accompanied them because the Confederates had already fired on an unarmed supply ship.
Davis knew what the orders to the ships were. They would not fire if the supply mission proceeded without opposition. firing on it would mean war. He also knew allowing the fort to be resupplied would cause him a political firestorm of outrage. As early as the 8th of April Davis had already decided that he would not allow a resupply of Fort Sumter. Davis had already decided there would be war if Lincoln attempted to resupply the fort.
Lincoln had a Constitutional obligation to defend Federal property and resupply Federal troops. Davis was under not such obligation. Lincoln knew that if he allowed Sumter to surrender without a fight it would also cause a political firestorm of outrage.