The war of words over American trade tariffs on Chinese exports and the expulsion of Russian diplomats may seem unrelated issues. But there is a connecting theme: the staggering US hypocrisy over its own aggressive behaviour.

This blatant American hypocrisy – beyond reason and respect for international law – marks a fatal descent into barbarism towards foreign relations. Dialogue and diplomacy are repudiated with a “might is right” attitude.

Washington took the initiative to propose slapping China’s economy with nearly $50 billion in levies on certain exports – claiming unfair trading practices conducted by Beijing. Then when China responded this week by announcing it would be reciprocating by imposing equivalent tariffs on American exports, the Trump White House threw up its arms in annoyance, saying that the Chinese decision was “not fair”.

Similarly, last week Washington took the decision to expel 60 Russian diplomats in support of tenuous Britain’s allegations that the Russian state had some involvement in the apparent poisoning of an exiled spy and his daughter in the English town of Salisbury on March 4. This week Moscow reciprocated by expelling 60 American diplomats from Russia.

As with China’s symmetrical response to US trade tariffs, Washington then declared that Russia’s expulsion of its diplomats was “not fair”. State Department spokeswoman Heather Nauert made the haughty comment that “Russia should not be acting like the victim here”.

So, let’s get this straight. Washington arrogates the right to take aggressive actions against foreign states, damaging the national interests of those states. But when the other side takes a reciprocal measure, the Americans complain that the measures are unacceptable and an affront.

Such an attitude in Washington is impossibly hypocritical, arrogant and intolerable. It certainly gives new meaning to American claims of being an “exceptional nation” – exceptionally hubristic.

Fears of a full-on global trade war with China have receded somewhat this week because the Trump administration sought to walk back from the proposed tariffs on Chinese exports. Earlier President Trump was bragging that he would easily win a trade war with China. But following Beijing’s announcement of penalties on American agricultural exports, aviation and cars, the White House is toning down the bellicose rhetoric – albeit still griping about China’s moves as “not being fair”.

On the expulsion of Russian diplomats, it should be recalled that there have been several rounds of such American sanctions, going back to December 2016 when the Obama administration expelled some 30 Russian envoys and their families over allegations of Moscow “interfering in US elections”. During the Trump administration, Russia’s diplomatic properties have also been shuttered and raided by US law enforcement officers.

All these American diplomatic censures have been launched on the back of unproven allegations of Russian interference in US democracy. The irony is that these claims have been made by Trump’s political enemies as a way to smear his presidency as somehow being a beneficiary of Kremlin subversion, yet his administration has ratcheted up the diplomatic tensions with Russia by expelling its diplomats over unfounded claims.

The American claims of Russian “cyberattacks” are of a piece with the recent British claims about Kremlin agents allegedly carrying out an assassination plot on its territory. The claims are always in the realm of assertion, with no verifiable evidence to support. Indeed, it looks as if both narratives on either side of the Atlantic are unravelling from the lack of credibility. US special investigator Robert Mueller can’t find any evidence of Russian collusion with Trump – after a year of probing and congressional hearings. Meanwhile, British government scientists are now saying they actually have no evidence that an alleged nerve poison apparently used against Sergei Skripal and his daughter Yulia was originated in Russia – flatly contradicting the high-flown assertions made last month by British Prime Minister Theresa May and her bumptious Foreign Minister Boris Johnson.

The point is that disputes between states must be resolved by dialogue and a basic mutual respect. Whether it is disputes over trade matters or politics. All the more so whenever alleged grievances are being levelled recklessly without any supporting proof or adherence to due legal process.

But the conflictual problem seems to stem from an ulterior agenda. American perceived grievances against China and Russia seem more about finding pretexts to pursue aggressive policy at all costs. Several foreign policy and military documents out of Washington have openly declared Beijing and Moscow as “rival powers”. This gets back to the issue of American global power relying on a unipolar hegemonic ambition, unable and unwilling to engage with China or Russia as mutual powers. Or anyone else for that matter in a multipolar world.

In order to pursue this dangerous ambition, Washington must – out of warped necessity – erode and cut off diplomatic engagement with China and Russia. That explains why Washington has initiated such aggressive moves over trade and expulsion of envoys. Ominously, it harks to the maxim of “war as a continuation of politics by other means” formulated by the Prussian military strategist Karl von Clausewitz (1780-1831).

What we are witnessing is a hollowing out of US diplomacy and its replacement with a policy of bellicosity. The Trump administration has gutted the State Department and its diplomatic corps.

This is inevitably a reprehensible decent into barbarism by Washington where international law and norms of dialogue are being repudiated out of hand. Why, for example, does Washington not take its alleged trade grievances with China to the World Trade Organization and resolve them in a civilized forum?

The degeneration of American diplomacy is perhaps most glaringly apparent when it hypocritically protests about “unfair” practices by China and Russia that merely reciprocate its own offensive behaviour.

When such arrogant delusion has taken hold, it does not bode well for civilized resolution and a peaceful international order. Because such an attitude violates the foundations of civilized multilateralism upon which international peace depends.

The arrogance of American unilateralism over trade bullying with China and the senseless diplomatic row with Russia is a disastrous resort to “might is right”.

American hypocrisy is a symptom of its degenerate diplomacy and contempt for international law. That in turn is a symptom of American democracy degenerating into a moribund morass. Blaming China and Russia is a desperate attempt to cover-up the inherent existential problems of American capitalism.