英語の文章を訳して下さい。
At the beginning of this period the British Merchant Marine had a shipping fleet totaling of 21 million GRT. In six months of unrestricted submarine warfare U-boats sank ¾ million tons of Allied shipping, scarcely denting the British merchant fleet; Whilst new building, and additions from ships seized, had more than made up this loss. On the other hand, serious offence had been given to neutrals such as Norway and the Netherlands, and brought the United States to the brink of war. This failure, and the various restrictions imposed on the U-boat Arm in the Atlantic area largely brought the campaign there to a halt, although it continued with little hindrance in the Mediterranean and elsewhere, where there was less likelihood of offending neutrals.
