Lusitiania was not a direct issue. It was sunk in May 1915, which was about two years before the US entered the war.
The uproar over the sinking led to Germany temporarily abandoning “unrestricted” submarine warfare, at least in theory. This gave UK an enormous advantage, as they could blockade and starve Germany with surface ships. Germany could only do the same to UK with subs.
In late 1916, early 1917 the German Navy “guaranteed” the Kaiser that they could bring Britain to her knees if allowed to use the U-boats without restrictions. This pissed off America, and the Zimmerman telegram put icing on the cake.
BTW, in late 1916 the Germans weren’t losing the war, but they weren’t winning either. The war was a stalemate, and the sub attacks were an attempt to break the stalemate.
The Balfour Declaration was very much a side issue at the time. Hardly anybody paid any attention to it. Anyway, it was Nov. of 17, quite some time after America jumped in.
The U-boat blockade was a red herring; the British blockaded the German coast, and we abided by that. The British government never let divers examine the Lusitania because of the widespread suspicion that it was carrying arms to Britain. Whatever the truth, it sank in 20 minutes compared to the Titanic, which took 2 hours.
The US entered the war in 1917 because Russia had surrendered, and Britain & France would have undoubtedly lost the war at that point. They were barely hanging, between the trench mutinies in the French army and the fact that they were running out of men (France lost 1.7 million men in WWI); over 1 million German and Austro-Hungarian troops became available with the Russian surrender on the Eastern Front (side note: critics of Operation Barbarossa often forget that Russia surrendered in 1917; rather they harken back to Napoleon’s failue 100 years before). The U-boat campaign was working, and all loans to Britain would be lost when they inevitably had to surrender as well.
Anything about “making the world safe for democracy” was hogwash; at the time the “sun never set on the British Empire”.
Like many things, this can be debated in circles forever.
Stop using logic with the newbie troll