Why have the Chechens long resisted Russian rule, and what actions has Russia taken under Putin to gain control of Chechnya?

Answer 1

Chechens are Sunni Muslims, which is ethnically different from Russia.
There have been two wars with Chechnya, but only the second war was conducted under Putin. The invasion of Dagestan and the terrorist bombings in Moscow led to a surge in anti-Chechen sentiment among Russians and to calls for resolute action against Chechnya. Russia's new prime minister, Vladimir Putin, decided to pursue an all-out second Chechen war.
In September 1999, Russian forces launched a furious attack that this time put them firmly in control of most of Chechnya and left Groznyy in ruins. Russians celebrated Putin as a resolute leader who would finally protect them. But in the years since 1999, much evidence has surfaced that the Russia's Federal Security Service (FSB), which succeeded the KGB, was actually responsible for the Moscow and other bombings. The contention is that the FSB sacrificed Russian civilians in a ploy to set the stage for a Chechen conflict that would consolidate Putin's power and popularity.
With Kadyrov, Putin implemented his policy of "Chechnization," using a handpicked and highly paid local ruler to carry out Moscow's will in Chechnya, quell the Chechen insurgency against Russia, and discourage any other would- be separatist movements.
This Russian government poured money into Kadyrov's Chechnya, investing in the reconstruction of roads and the urban infrastructure of shattered Groznyy.