Moskovskij Komsomolets senior journalist Andrey Kamakin tries to figure out by process of elimination, the identity of the unnamed country Vladimir Putin was referring to, when he promised to knock out the teeth of those coveting Russia's territory. Kamakin's educated guess is that Putin was referring to China. The Chinese have not forgotten that they were forced to cede territory to Russia in the nineteenth century and an overcrowded China finds it unfair that these nearly deserted territories should be owned by Russia. Kamakin also recalls that the last foreign attack on Russia was launched by China. The article in the mass-circulation publication again shows that despite official claims about a strategic Russia-China partnership, suspicion of China lurks below the surface.
Kamakin's article follows below: 
A 2017 memorial service for Russian soldiers, who fell in battle defending Damansky Island against the Chinese (Source: Aif.ru)
"Vladimir Putin promised to knock out the teeth of those, who are about to 'bite off our territories.' According to the president, recently the enemies [of Russia] have become emboldened; they openly put forward territorial claims to Russia. However, he didn't directly name these enemies, who covet our lands. And that was a mistake. [I understand that] state secrets should be maintained, but we must know what to prepare for, and from what direction will the vile enemy strike. And who is this enemy? Anyways, let's try to guess for ourselves.
"Seemingly, there was a hint in another of Putin's statements, which was made at the very same meeting of the 'Victory' organizing committee, 'Some even dare to state openly that it's unfair that wealth of such region as Siberia belong to Russia alone.' Essentially Putin's words are a paraphrase of a statement attributed to Madeleine Albright, who served as the US Secretary of State in the Bill Clinton administration (from 1997 to 2001).
"But in fact, this trail is absolutely false; Albright never said anything of the sort. However, according to some sources, she thought so.
"In 2006, FSO [Federal Protective Service] General Boris Ratnikov, who passed away last winter, revealed to the newspaper Rossiyskaya Gazeta the 'sensational' details of an operation by 'one of the most secret state security units,' whose methods had roots in the 'magical practice of ancient priests.'
"'A few weeks before the bombing of Yugoslavia by the US Air Forces began, we held a séance and were able to connect to the subconscious of the US Secretary of State, Albright. In Madame Albright's thoughts, we discovered a pathological hatred towards the Slavs. She also resented the fact that Russia has the world's most abundant mineral deposits. She believed that in the future, Russian mineral reserves should be controlled not by one country, but by all of humanity under the supervision of the US, of course,' claimed Ratnikov
"Alas, one, should not regard treat such 'intelligence' with complete confidence. Only those, whose own psyche suffers from serious pathological changes, can completely trust it. Besides, Putin clearly stated that he did not mean not someone's thoughts, but actual public statements. So, to put it briefly Albright becomes irrelevant.
"Let's try to solve this puzzle geography-wise. We have a location - Siberia. What countries does Russia border upon in Asia? We have the longest border with Kazakhstan (7598.8 kilometers) and China (4209.3 kilometers). Let's try to further narrow down the possibilities. Has any of these two countries ever "dared to openly claim" that Russia does not own Siberia rightfully? Well, unfortunately both countries did.
"For example, let's quote the Chairman of the Kazakh Union of Military Operations Veterans on the Tajik-Afghan border, Murat Mukhamedzhanov, who described his conversation with the State Duma deputy, Yevgeny Fedorov. The Russian deputy's statements that Russia has the right to initiate a return of territorial 'gifts' to Kazakhstan, made in Soviet times became grounds for a polemic.
"'I [Fedorov] said that Russia violated the law in its withdrawal from the Soviet Union', recounts Mukhamedzhanov. I said [in reply], 'In that case return Orenburg, Omsk, Tomsk, Astrakhan, Tyumen, the Ural lands, Altai Territory to us ... 1.5 million Kazakhs and many other peoples live there ... The first congress of Alash residents was held in Orenburg ... This is in fact our land, our cities ...'
"However, the PRC makes infinitely more statements of this sort.
"Nostalgia for the 'northern territories' 'annexed' by Russia under the Aigun (1858) and Peking (1860) treaties is an integral and absolutely legitimate part of the national historical memory. Back then the Qing Empire ceded the territories of today's Primorsky and Khabarovsk krais and the Amur oblast to the Russian Empire.
"No territorial claims on Russia were yet put forward openly. However, there are many statements in line with the following, 'It is unfair that one and a half billion Chinese should be crowded into such a limited territory, while there are nearly deserted lands nearby, which were once taken from them [the Chinese] to boot.' By the way, this is almost a literal quote from an article published a few years ago in a Chinese newspaper.
"Economically speaking, China is already actively reclaiming the 'northern territories' (with Russia's help and authorization of course). China's wealth in many ways entwines Siberia– its forests, gas, oil, ore and other raw materials.
"Finally, let's ask ourselves the final telltale question, 'who was the last one that tried to 'bite off our territories' using armed force?" After the Great Patriotic War, our country was only once attacked by a foreign power. And the aggressor was not America, nor England, nor the 'aggressive bloc' NATO, but the very same 'fraternal' China.
"I'm talking about events that went down in history as the 'Sino-Soviet border conflict on Damansky Island' (March 1969, Primorsky Krai, Ussuri River).
"Some understanding of this battle's ferocity is provided by the memoirs of the Hero of the Soviet Union, Yuri Babansky, who at that time served as the commander of the "Nizhne-Mikhailovka" frontier outpost, 'After 20 minutes of the battle, eight out of 12 soldiers remained alive, after another 15minutes – only five. Of course, it was still possible to retreat, return to the outpost and await reinforcements from the squad. But we were seized by a livid anger towards these bastards that in those minutes we wanted only one thing - to kill as many of them as possible, to kill for our comrades, for ourselves, for this land that no one needs, but which is still ours.'
"The Soviet side lost, according to official data, 58 people dead, and 94 wounded. Five participants of the clash were awarded the title of Hero of the Soviet Union, including three soldiers [awarded] it posthumously.
"Half a century ago, [Damansky] island was successfully defended, but in the end the territorial dispute was resolved in China's favor. In the 2000s, Damansky island fell under the PRC flag, and an entire series of other border territories.
"The total area of the territories transferred to the PRC after a 'border demarcation' constituted 337 square kilometers. However, as the saying goes, the appetite grows with eating.
"Let's be honest: this quite slim and logical-looking hypothesis is upended by the indisputable fact that China is now our bosom buddy and a strategic partner. Well, the president simply couldn't make such statements about a strategic partner!
"Or could he? Maybe due to some diplomatic considerations and delicacy, he decided not to dot the I's? Anyways, as one old anecdote put it, 'again this unbearable suspense.'"
Andrey Kamakin (Source: Mk.ru)
 Mk.ru, May 21, 2021.