Nobody ever won a war by sitting on the defensive. This applies to Ukraine's prospects for defeating the Russian invasion notwithstanding the tactical superiority of the defense over attackers.
Russia appears to be on the offensive:
Ukrainian Main Military Intelligence Directorate (GUR) Head Lieutenant General Kyrylo Budanov stated on January 30 that the Russian offensive in Ukraine is currently ongoing and that Russian forces aim to reach the Zherebets River (in the Kharkiv-Luhansk Oblast border area) and the administrative borders of Donetsk and Luhansk oblasts. Budanov forecasted that Russian forces would fail to achieve these objectives, however, and would likely be “completely exhausted” by the beginning of the spring.
ISW doesn't think the offensive will achieve more than tactical gains. Despite this, it appears to me that the military is under pressure to attack when it should be building up forces for a significant offensive:
Russian Defense Minister Sergei Shoigu stated on February 2 that Russian forces retain the “strategic initiative” along the entire frontline in Ukraine, a notable departure from Shoigu’s previous characterization of Russian operations as “active defense.”
Is holding the strategic initiative a simple statement of fact (excepting the Kherson front) or an indication that Russia will attack with whatever it has available?
It has boggled my mind that Russia hasn't built up a force to resume offensive operations north of the Kharkov region. Why wouldn't Russia use its superior numbers to extend the front to the north and northeast?
But Putin seemingly hopes Russia can absorb casualties along the current truncated active front better than Ukraine can. I was way off before the big invasion on this issue. But is Putin right about the Russian willingness to keep dying?
The Kremlin censored a protest by wives of mobilized soldiers in Moscow on February 3 likely to suppress any possible resurgence of a broader social movement in support of Russian soldiers and against the regime.
Losses will certainly prevent Russia from accumulating significant forces to achieve significant gains. Assuming Ukraine doesn't crack from morale or supply issues.
ISW rightly notes that Ukraine can prepare to win while on the strategic defensive. But there is a danger of sitting on the defensive too long:
Ukrainian forces will likely be unable to husband materiel and personnel while defending against Russian offensive operations, localized or large-scale, that are meant to prevent them from doing so. Ukraine would risk consuming resources it hoped to conserve for its own counteroffensive operations in efforts to stop continuing Russian attacks, likely while losing ground, if it went over to the strategic defensive as some US officials are apparently recommending. The side in war that holds the initiative generally has the advantage, and it is unwise to suggest that Ukraine should cede that advantage to Russia for longer than is absolutely necessary.
As I commented in 2022, nobody ever won a war by staying on the defensive, notwithstanding the rote repetition out of context that defending requires fewer troops than attacking:
First, people often get the 3:1 rule wrong. It is a ratio of power--with a number of factors contributing and not just troop numbers engaged--for tactical battles, and not a measure of necessary troop strength superiority overall in a war.
Second, in military parlance there's another saying. "Nobody ever won a war by sitting on the defensive."
Third, while being on the offensive is harder than being on the defensive, having the initiative has a number of advantages.
As an aside, I wrote a better post for the 3:1 rule from The Dupuy Institute example than the one linked in the quote.
I then went into the advantages in that 2022 post that I won't repeat here. Check it out if you like.
Recall that in World War II, Russia was able to get large advantages in men and materiel on their offensive fronts in large measure because after Kursk, Germany was too weak to go on the offensive even on limited sections of the front. This allowed Russia to thin out their troops on non-offensive sector parts of the front to get big superiority at the point of attack. And the Germans were unable to exploit the thinner Russian forces elsewhere--even if Germany had been aware of the vulnerabilities.
That German inability to seize the initiative was a tremendous safety net for Russia which knew it could take those risks in order to keep hitting the Germans.
If Ukraine can't seize the initiative, it must defend. And building fortifications is good. But don't dare think that this is the path for a low-cost Ukrainian victory. At best it is a strategy for losing less than it might.
At worst, with that safety net of knowing Ukraine can't exploit any Russian weaknesses, Russia conquers Ukraine after a long fight. And while we may later marvel at how many casualties Ukraine inflicted on the inferior Russian troops, in the end Ukraine will be conquered.
The West must not throw Ukraine to the bear and hope that sates its appetite:
Once aid expands to allow greater Ukrainian military assertiveness, instead of pure survival, and simultaneous long-term security commitments, including the prospect of NATO membership at the alliance summit in July, a path to peace and stability would be possible by this year’s end.
Putin has more territorial ambitions. Even if he pushes elsewhere first before returning to his NATO obsession.
Have a super sparkly day.
UPDATE (Monday): Russia builds up reserves:
Russia's reported reserve concentrations throughout Ukraine largely align with Russia’s assessed priorities along the front, although they are not necessarily indicative of future Russian operations. Ukrainian military observer Kostyantyn Mashovets stated that Russian forces currently have 17 regiments, 16 battalions, and two regiment-battalion level tactical detachments in reserve. Mashovets stated that there are about 60,000-62,000 total Russian personnel in reserve units, but Russian forces have only equipped about 20,000 tactical and operational-tactical level reserve personnel with weapons and equipment.
Will Russia expend them to maintain the illusion of strategic initiative to take minor objectives? Or will Russia equip, organize, and deploy them into a significant force able to achieve decisive results?
Will Ukraine contest Russia's strategic initiative to deny the ability of the Russians to mass their reserves? Can Ukraine without immediate resupply?
UPDATE (Tuesday): Is Avdiivka about to fall to the Russian invaders?
I worry less about Ukraine losing the city than I worry about Ukraine losing their troops defending that narrow salient if the Russians manage to encircle the city. Preserve the army, I say.
Unless Ukraine is poised to counter-attack any Russian penetration and engage them in an open battle kill sack rather than trying to batter through Russian minefields, fortifications, and artillery fire.
UPDATE (Thursday): Russia redeployed heavily armed National Guard units to the Belgorod border region:
ISW also previously assessed that Russian forces may launch tactical diversionary cross-border raids into Kharkiv Oblast from Belgorod Oblast to distract and pin Ukrainian forces away from the Kupyansk-Svatove-Kreminna axis, where Russian forces are currently pursuing offensive operations[.]I've long been puzzled why Russia doesn't try to stretch Ukraine's defenses by striking into the less-defended north and northeast.
