Don't sink the goddamn Lusitania
The US already did support GB with weapons and munitions even as they were bound by their declaration of neutrality. They were warned by the Germans: en.wikipedia.org/wiki/RMS_Lusitania#Last_voyage_and_sinking
This ship was FULL of ammunition and weapons...you were warned about breaking your neutrality and that the ship was entering war territory.
A dive team from Cork Sub Aqua Club, diving under license, discovered 15,000 rounds of the .303 (7.7×56mmR) caliber rifle ammunition transported on the Lusitania in boxes in the bow section of the ship. The find was photographed but left in situ under the terms of the license. In December 2008, Gregg Bemis's dive team estimated a further four million rounds of .303 ammunition were on the ship at the time of it's sinking.
...and the british propaganda used it to the fullest to bring the US on their side into the war.
Congrats for falling for that trap!
Professor William Kingston of Trinity College, Dublin has said, "There's no doubt at all about it that the Royal Navy and the British government have taken very considerable steps over the years to try to prevent whatever can be found out about the Lusitania".