Because it made the Americans mad.
Allow its merchant shipping to be sunk and its citizens to be killed by German U-Boats.
The main threats to American trade historically included piracy, especially in the Mediterranean and the Caribbean, which disrupted shipping routes and endangered merchant vessels. Additionally, colonial rivalries and conflicts, such as the War of 1812, posed significant challenges to trade through blockades and hostile actions. Economic competition from other nations, as well as tariffs and trade restrictions, also impacted American trade dynamics. In more recent times, geopolitical tensions and global supply chain disruptions have emerged as critical threats.
There are lots of different threats like cross cantamination between contries. Sighed 9er
British restriction and interference of American shipping on the high sea
Privateers or Merchant Mariners help win the Revolutionary War. To add to this, they issued Letters of Marque to privately owned, armed merchant ships and Commissions for privateers, which were outfitted as warships to prey on enemy merchant ships
IJN subs were deployed for "fleet warfare", not merchant raiding. The costly job of sinking allied warships fell to the IJN sub fleet. It's estimated that IJN submarines sank less than 50 merchant ships during the war.
War Shipping Administration was created in 1942.
103 merchant ships were sunk in world war one
threats of another war
a third party destroyd a shipping line they told the zoffs the fuzzians did it and vice versa
The british were the one interfering with the American shipping on the war of 1812
Ww ii