You are entitled to your own opinions, but not your own set of facts. He sent 4 warships, 3 tugboats, and an ocean going passenger ship loaded with Union troops and munitions.
"Some of the preparations were completed with relative ease. Fox immediately engaged the services of the large civilian steamer Baltic to carry the bulk of his expedition. Other elements of Fox’s plan did not come together so easily, however. The Navy had placed all its commissioned ships in the Atlantic waters at Fox’s disposal, ordering the naval warships Powhatan, Pocahontas and Pawnee and the revenue cutter Harriet Lane to be placed in readiness for sea service."
"Hiring the tugboats for the mission proved to be the most difficult task of all for Fox. Because obvious danger surrounded the endeavor, Northern shipowners were reluctant to lend their tugs to the cause. Only the payment of the most exorbitant rates, Fox complained, finally secured the services of three tugs– Yankee, Uncle Ben and Thomas Freeborn."
"Finally, when all preparations for Fox’s mission were complete, the various vessels sailed for Charleston. Each made its way south separately. On April 6 the frigate Powhatan, under the command of Captain Samuel Mercer, prepared to sail from New York. Other vessels, including the revenue cutter Harriet Lane and tugs Uncle Ben and Yankee, soon made their way south. The sloop of war Pawnee, under the command of Commander Stephen C. Rowan, sailed from Norfolk, Va., on April 9. Baltic, with Fox on board, dropped down to Sandy Hook at the mouth of New York Harbor on the evening of April 8 and put out to sea the following morning."
It was an attack. The ship's orders said to use force if resisted.
Curiously enough, those were pretty similar to orders Jefferson Davis gave CSA Gen. Beauregard -- demand surrender, attack "reduce" fort if not complied.
The difference is, of course, Beauregard was under orders to take the fort by whatever means necessary while Union forces were ordered only to replenish it, by force if necessary.
As it turned out, only Confederates used force in anything other than self defense.