So when Palmerston appointed young Canning as ambassador to Russia, after spending a solid three to four months in St. Petersburg, Canning had yet to even catch a glimpse of Tsar Nicholas I.
Unable to meet the Tsar meant that he, as an ambassador, truly could not fulfill his duties. Therefore, as a last resort, Palmerston had no choice but to relocate Canning, sending him back to the Ottoman capital of Constantinople.
Why not someplace else? Naturally, it was because the Sultan had previously proven his tolerance of others, and Palmerston was worried that other countries besides the Ottoman might not accommodate the bluntness of young Canning.
After all, only Heaven knows how many countries this man has insulted.
If the rulers of other countries were to ignore Canning, as the Tsar had done, would he have to find yet another new position to try out?
Replacing an ambassador within a short period could be explained as a normal reassignment.