If the attacker must travel a considerable distance just to reach the defender’s territory, the amount of force it can project is reduced by the costs of transporting and supplying the projected force, as well as the costs of defending long lines of communication.
Ukrainian offensive against the oblasts bordering Crimea carries further hard choices, forcing commanders to fight through layers of defensive positions more than 10 kilometers deep in Zaporizhzhia or to cross the Dnipro River, a difficult operation that carries the subsequent challenge of defending a beachhead from a counterattack.
against Ukrainian efforts to break through to Melitopol or Berdiansk cities. These preparations reflect the high military and political value Russia attaches to control of Zaporizhzhia Oblast. A Russian collapse like the one seen in Kharkiv in 2022 that allowed Ukraine to approach or liberate these cities would pose a serious threat to Russia’s operations in Ukraine.
These spans of water are wide enough that they would require amphibious assaults, one of the most complex and demanding operations a military can attempt
A Ukrainian attempt to push through either of these cities is extremely unlikely for an excellent reason: if Ukraine attempted to assault these cities directly, its offensive would become bogged down in urban combat.
areas north of Kreminna
these fortifications lie just a few kilometers behind a string of towns that hug the eastern bank of the Krasna River. The houses in these towns would provide ready-made fortifications from which the Russians could fight, while Ukraine would be slowed by the need to conduct bridging operations
North of Preobrazhenne
For example, there is an apparent gap between the towns of Pershotravneve, Mykolaivka, and Arapivka: a potential opening less than 30 kilometers by road from Kupiansk, a city in which Ukraine could conceivably mass forces. As is the case in Zaporizhzhia, areas without fieldworks are not necessarily undefended
dragon theeths
These obstacles are most effective when connected to one another by concrete linkages underground and partially buried.
Some images appear to show dragon’s teeth without underground connections. Other images appear to show dragon’s teeth sitting on top of the earth rather than partially under it. One image posted on several Russian websites also appears to show that some of the dragon’s teeth used by Russia are not entirely made of concrete and are already suffering environmental damage in Ukraine.[27] It is impossible to draw sweeping conclusions about the overall quality of Russia’s defenses from these images, but they are enough to suggest that there are variations in the quality of defenses across the line that can be exploited by Ukraine with good intelligence.
For example, Ukrainian forces could use a combination of advanced technology and UASs or loitering munitions—including those supplied by the West—to conduct UAS “swarms” against Russian defensive positions. As interviews with Ukrainian military officials indicate, Ukraine is investing significant time and resources into innovations such as swarming tactics designed to maximize target saturation and overwhelm Russian defenses.[39] UASs could also be employed to probe for gaps in Russian lines, locate Russian reserves or artillery systems, or provide artillery-like effects in support of high-mobility units exploiting a breakthrough.
1967 Six Day War
Israel developed an effective blitzkrieg strategy that relied on armor to inflict a decisive defeat against its Arab adversaries
If we opened the attack and effected an armored breakthrough into Sinai, the enemy would be forced to fight according to the moves we made.
For example, a major breakthrough in Zaporizhzhia could severely threaten the viability of Russia’s land bridge linking Russia’s Rostov region with Crimea. Even a breakthrough in the less-densely defended Luhansk Oblast could provide significant benefits by proving that Western support for Ukraine continues to bear fruit, removing Russian units from the battlefield, and sowing further dissent within Russia itself.
https://www.csis.org/analysis/ukraines-offensive-operations-shifting-offense-defense-balance