Russian Brigades In Southern Ukraine Depended On One Major Bridge. Now They’re Cut Off From Resupply.

Two days after a powerful explosion rocked the $4-billion rail and road bridge across the Kerch Strait, the narrow waterway separating the Russian-occupied Crimean Peninsula from the Russian mainland, the Russians are scrambling to re-open the span.

It’s not hard to see why. The 11-mile-long bridge is the most important overland line of communication between Russia and Russia’s forces in southern Ukraine. There are ways around the bridge, but they’re narrow, slow and vulnerable to Ukrainian attack.

Which leaves Russia with a choice. Fix the Kerch Bridge fast, or risk its brigades on the southern front—already weakened by months of bombardment—starving on the brittle vine of Russia’s collapsing supply lines.

The Russian government began work on the Kerch Bridge just a year after its forces annexed Crimea and invaded eastern Ukraine’s Donbas region. The bridge, along with sea and air transport, helped the Russians to build up a powerful garrison in Crimea. A garrison that, back in late February, rolled north as part of Russia’s ever-widening war on Ukraine.

The bridge with its twin rail lines and two lanes for cars and trucks by far is the most efficient way for heavy equipment and bulk materials to get to Crimea and then north to the occupied Kherson, the locus of Russian control over southern Ukraine south of the free city of Mykolaiv.

The bridge’s extreme value explains why Ukraine apparently devised some method of striking it from a distance of 175 miles. None of the rockets and ballistic missiles Ukraine has copped to possessing can travel that far. The Ukrainian air force, despite its surprising durability in the face of Russia’s overwhelming aerial advantage, has never struck that deeply behind the front line.

The massive explosion that struck the bridge on Friday could only have resulted from a powerful bomb. Packed in a truck, perhaps, and remotely triggered by a team of saboteurs. The blast destroyed several civilian vehicles, presumably killing their occupants, and dropped one lane of the two-lane road bridge into the Kerch Strait.

The attack set ablaze a passing train with tanker cars. The train fire, burning at a temperature of 1,000 degrees Fahrenheit or hotter, almost certainly weakened the steel in the bridge’s structure. A further collapse wouldn’t be surprising.

In any other country, at any other time, authorities would totally shut down the bridge for what could be many months of extensive repairs. But the Kremlin had little choice but to reopen the bridge—or at least look like it was reopening the bridge in order to project strength. Within a day, the Russians were allowing a few vehicles onto the bridge’s surviving lane. Inspection of the damaged rail line was ongoing.

The Kerch Bridge still stands. But its capacity is a fraction of what it was just two days ago. Ferries have begun shuttling people and cars across the Kerch Strait as thousands of Crimea residents flee the peninsula.

The dilemma that was apparent on Friday remains unanswered. How does the Kremlin intend to resupply its field armies in and around Kherson? The dilemma grows more urgent by the day as a trio of Ukrainian brigades continues its aggressive counteroffensive in the south.

The 17th Tank Brigade is rolling toward Kherson’s outskirts from the west. The 128th Mountain Brigade is racing south along the wide Dnipro River east of Kherson while the 35th Marine Brigade attacks east of the Inhulets River north of Kherson.

The Ukrainian assault already has destroyed or scattered a Russian coastal-defense brigade and driven back a lonely and misplaced Arctic brigade. The Russian 49th Combined Arms Army, the backbone of the Kherson garrison, could be next to fall if the Kremlin can’t push supplies into the area.

But until the Kerch Bridge reopens, there’s just one way in—via a railway threading from Russia through eastern Ukraine to occupied Melitopol. The problems are myriad. For one, the eastern rail line is close enough to the front near Donetsk that it could come under intensive attack. Secondly, there’s no major direct rail between Melitopol and Kherson.

To get to the 49th CAA by rail, supplies would need to travel south from Melitopol into Crimea, then back north to Kherson—a slow and inefficient route that adds time and risk. The alternative is to unload the trains in Melitopol, load up trucks and drive the supplies west to Kherson. But the Russians never had enough trucks. And they’ve got even fewer now that the Ukrainians have destroyed hundreds of them.

As engineers prod the charred remains of the Kerch Bridge, the severity of Russia’s logistical problem is becoming clearer. The Russians’ supply lines into southern Ukraine were fragile before the attack on the Kerch Bridge. They’re even more fragile now.

It might take a few weeks for the major implications to manifest. The 49th CAA in and around Kherson won’t immediately starve. But it will starve. And when it does, it will retreat, surrender or die in place as Ukrainian brigades close in.