Lincoln didn't say he wouldn't reclaim federal property in his inaugural address, but he wisely dropped a threat to do so from his first presidential speech to give his new administration time to get organized before tipping his hand to the rebels.
The South, who truly believed they had the constitutional right to secede, could probably argue that actions by Lincoln to reclaim forts located within their states and enforce US duties at their ports were acts of war.
The Confederates could take any ridiculous position they wanted and often did, but the rebels were the ones who initiated the Civil War by seceding and attacking federal forts, not Lincoln.
It is best that you not talk about ridiculous positions, ravinson, given that Lincoln argued that the nation preceded the states.
To me, the Tenth Amendment guarantees the right of states to secede. However, force of arms was really what resolved the secession question, like duels established which conflicting witness was telling the truth.