Although the Earl of Clarendon verbally refused to answer James Buchanan's questions, every word he spoke hinted to James Buchanan that the Kingdom of Britain's refusal of the United States of America was related to the French Empire, and significantly so.
Therefore, the Earl of Clarendon's refusal to answer was an implicit consent in James Buchanan's ears.
What on earth is that guy Mason doing! He can't even handle such a small matter!
James Buchanan internally cursed Mason, who was far away in Paris.
James Buchanan put in a lot of effort, both in relationship-building and gift-giving (to Palmerston and Newcastle), to successfully negotiate with the British side. According to James Buchanan's estimation, it would only take about two months before American merchant ships could sail unimpeded in the Baltic Sea and earn gold coins from the Russian Empire.
