The Russian Agents
Even though these two guys—one Russian and one Frenchman—are the main antagonists of Kim, we don't ever learn their actual names, and they don't appear in the novel for long at all. They represent the first real enemies to the British Empire that Kim has to face as a not-quite-agent; they have been trying to bring two of the five rebellious northern kings, Hilas and Bunnar, over to the side of the Russian Czar in the competition between the British and Russian Empires over control of India.
But in fact, the threat these agents represent to Britain is so insignificant that it takes, like, three chapters for Kim to wrap up their plot line. And anyway, they totally manage to shoot themselves in the foot in their mission to turn the local kings against the British Empire—Kim just has to stick around long enough to grab their incriminating papers once they have ruined things for themselves.
To be clear: the reason these two are unsuccessful is not because Kim does anything so very heroic (though he does exchange gunfire with these enemy agents as they try escape the Himalayan valley where they have all wound up).
Nope, what actually spoils their fun is the Russian agent's fight with the lama over his painting of the Great Wheel of Existence. When the Russian agent hits the lama for refusing to sell the painting to him, he totally spoils his chances of convincing the highly religious people of the Himalayas to join his side. What defeats the Russian agents is their own arrogance and ignorance of the local culture—whereas Kim knows India inside and out, these two guys have no real feel for the motivations and customs of the peoples of India, so their efforts at espionage are completely wasted.
The fact that Kipling brings in these two European agents only to dismiss them almost immediately implies that he refuses to take seriously any empire that is not the British Empire. The insignificance of these guys actually makes a political point all on its own: Kipling seems to be implying that (1) we need guys like Kim to defend British India, but (2) Britain and India have been brought together so strongly by their shared history together that their bonds will almost defend themselves.