Story by Matthew Chance of CNN
ANALYSIS: Barely a week since Vladimir Putin secured his fifth presidential term, Russia has been plunged into carnage and disarray.
The appalling attack on the vast Crocus City Hall concert venue and shopping complex near Moscow, which has been claimed by ISIS, has left hundreds of innocents killed or injured.
The four men suspected of carrying out the attack were arrested near Russia's border with Ukraine, Russian authorities said. Putin said they had planned to cross into Ukraine - Kyiv has denied any link with the attack and warned Russia could use it as an excuse to escalate its invasion.
Amid fears of more attacks, security has been tightened at key transport hubs across Russia. Public concerts and sporting events have been postponed.
This is hardly the stability and security for which so many Russians voted for President Putin.
For years, the Kremlin strongman has been cast as a leader able to guarantee order in this vast, turbulent country.
But Russia today seems more insecure and volatile than at any point in Putin's 24 years in power.
The Kremlin's brutal war in Ukraine, now in its third horrific year, has cost Russians dearly. The military doesn't publicize casualty figures, but US estimates suggest more than 300,000 Russians have been killed or injured.
Many troops mobilized last year have still not been rotated from the frontlines, provoking an outcry from anxious relatives. As the war drags on, fears are growing among many Russians that the draft will be stepped up, sucking even more into the terrifying Ukrainian meat grinder.
Meanwhile, Ukrainian drone strikes and cross border raids by Ukraine-based Russian militias opposed to the Kremlin continue apace.
At the Ukrainian front, Russian forces appear to have the military initiative at present, but the poor performance of Russian commanders and weaponry over the course of the war has fueled an entirely unexpected stream of instability and internal dissent from bloggers and military hardliners enraged at the incompetence of those in charge.
The mutinous uprising last year of Yevgeny Prigozhin, the leader of the Wagner mercenary group who was demanding the dismissal of the Russian high command, was a shocking, unprecedented challenge to Kremlin authority.
His fiery death in a mysterious plane crash shortly afterwards permanently removed any Prigozhin threat. But other disgruntled hardliners may emerge.
In the same way, the recent death of Alexey Navalny, Russian most prominent opposition leader, has permanently silenced a vocal Kremlin critic. But the thousands who attended his funeral in Moscow, or who turned out to vote in a Midday Against Putin mass gathering at polling stations on the last day of the presidential election, indicate a base of discontent.
But now, the focus is firmly on the apparent reappearance in Russia of large-scale Jihadi terror attacks, unrelated to the Ukraine war or domestic opposition to the Kremlin.
To make matters worse, the US and other Western governments warned of intelligence suggesting such an attack in early March. US officials say they have been notifying Russia on the intelligence for months.
But for some reason, Putin chose to ignore this, describing the warnings as a "provocation... to intimidate and destabilize our society".
Perhaps it was distrust, with US Russian relations at such an historic low. It could also have been that the US intel was just too vague or not actionable.
But for a leader who has promised security and stability to Russians, a major attack on Russian soil is yet another powerful blow.
CNN
