Pakistan, Aug. 6 -- US President Donald Trump's threat to impose heavy tariffs on India over its Russian oil purchases may go down as the moment that finally dismantled the myth of India's diplomatic invincibility. For years, New Delhi has enjoyed strategic indulgence from Washington unmatched by any other regional player.

It styled itself as the natural counterweight to China, lobbied Western capitals to sideline Pakistan, and marketed its balancing act between Moscow and Washington as "strategic autonomy." Trump's outburst makes one thing clear: the West's tolerance for India's double game is wearing thin. That too, fast.

The past few news cycles have brought what is arguably the first serious public rebuke from Washington in over a d...