She was sunk on 19 August 1915, during the First World War, by German submarine SM U-24, 50 mi (80 km) south of Kinsale, causing a major diplomatic incident.

Arabic was fitted with twin-screw propellers driven by separate sets of quadruple expansion engines arranged on the builders' "balanced" principle.

Indeed, the last note, of 21 July, that Wilson sent took the form of an ultimatum, to the effect that the US would regard any subsequent sinkings that harm American citizens as "deliberately unfriendly".

Senior staff at the Foreign Office wrote angrily: "The attacks on the SS Orduña and the Arabic prove that new incidents with America are possible at any time.

The fact that the ships were heading out from the UK undercut all of the German excuses about the Lusitania carrying munitions, and indicated that any submarine captain could cause war between Germany and the US at any time.

He was supported by Army leader Erich von Falkenhayn who considered American involvement to be disastrous, likely leading to other neutral countries joining the Entente as well.

Meanwhile, Grand Admiral Tirpitz and Head of the Admiralty Staff Gustav Bachmann, naval leaders deeply involved in the submarine war, were opposed to all of the Chancellor's proposals.

Falkenhayn countered that the last six months showed the submarine to be simply not an effective weapon, and in a fury the Chancellor declared that he would not leave "until His Majesty had ruled in his favor".

The Kaiser issued direct orders on a suspension of the submarine campaign and Bachmann was removed, to be replaced by Henning von Holtzendorff who was thought to be closer to the Chancellor.

Tirpitz offered to resign his post as Naval Secretary and thus cause public outrage, but this was rejected, and instead his access to the Kaiser was strictly limited from this point on.

On September 6, the SM U-20 (ironically, the same culprit behind the Lusitania incident) sunk the outward-bound hospital ship RMS Hesperian, and then the Americans received a note on the next day defending Schneider and thus refusing to formally disavow his actions.

While the Hesperian crisis was defused by the Germans lying and claiming there were no submarines operating in the area,[20] the British crew of the Arabic said under oath that they were not attempting to ram, and the Foreign Office decided to accept their testimony while still refusing to disavow Schneider and "dishonor" the Navy.

The Chancellor only found out on October 26, at which point the reaction from America was such that the Foreign Office could only issue a cleverly veiled response to satisfy the Navy, and reprimand Bernstorff strongly in secret.