[Goose]

I agree that there is no way to just play defense and win.  I think Russia assumed that its "offense" would so over power Ukraine's defense early on that the war was over before it started.  Three and half years later we know that didn't work.  Ukraine has shown if you are smart and creative you can find new ways to do old things that changes everyone's thinking and forces the other side to rethink their plans.

For certain Russia (and virtually everybody else) expected Ukraine to collapse very quickly. At that point neither Russia nor Ukraine was thinking in terms of an Iskander vs Patriot battle going on for even weeks, let alone years :-). Ukraine had no Patriots at that point. Ukraine has indeed shown an ability to adapt to a very unique situation. While all wars are "unique" in some aspects, the Ukraine ware is totally unlike anything previously observed. Ukraine was fortunate to be attacked by a country that had no effective military (or political except for Putin) leadership and no trained, motivated military force that was prepared to fight Ukraine. This is an almost unheard of event in history. That gave Ukraine the precious gift of time. "Ask anything of me but time". Ukraine also had allies that gave technology to Ukraine that Ukraine could never afforded on their own nor been able to quickly produce. Ukraine has made good use of their opportunities and is holding on by cleverly Macgyvering together an effective military force from piles of differing components. It is however highly improbable such a scenario will play out in the future. For that reason, IMO one has to be very, very careful generalizing from events in Ukraine to future conflicts.

From what I have read, the Patriot sometimes has a hard time intercepting Iskandar missiles.  Do they still have any old S300 systems that might work?

S-300s and S-400s would undoubtedly fare even worse against a modern Iskander-M. The Iskander-M always was "advertised" to have certain anti-interception enhancements over a simple "ballistic" missile. A missile following a ballistic trajectory uses its rocket engine(s) to reach a certain altitude and then falls on its target. Once the engines burn out, the trajectory of the ballistic missile is completely mathematically predictable unless the missile can maneuver. Unlike almost all previous SRBMs the Iskander-M can maneuver, at least to some degree. The forces involved when a missile is falling out of the sky at Mach 5+ are such that no "sharp turns" are possible but tweaks are.
 
The Iskander-M was always known to have depressed trajectory capability. The purpose of that was to trade off some range in exchange for reducing the response time available for the ABM. This has been a Russian specialty going back to the 1970s. Soviet submarines in the Sea of Cortez anybody :-). Patriot doesn't have to do anything "special" to deal with it. The continuously updated tracking solution will work fine when the SRBM does become visible. The Iskander-M also has other defensive capabilities. Supposedly it can use a jammer to jam the radar of the ABM. AFAIK we haven't heard about that happening in Ukraine. The Iskander-M can be programmed to maneuver slightly (subject to g loading) at predetermined points in its trajectory. It is very probable the Patriot tracking algorithms used in Ukraine are not designed to accommodate such maneuvers. A ballistic trajectory is assumed. In some cases better tracking algorithms may be available but not enabled for use in Ukraine. That situation may persist.
 
It must also be recognized that the Patriot (like the Iskander-M) has a kinetic energy budget and g loading limitations. The Patriot may have committed itself to an intercept at a certain place and time. If the Iskander-M maneuvers it is entirely possible the Patriot has no feasible response. The Iskander-M may beat it to the "new" target and there is no answer. This situation becomes more likely as the Patriot is asked to cover a larger footprint. As a point defense system Patriot can depend on the fact the incoming missile must eventually come toward the Patriot. As an area defense weapon that is not true. The Patriot might have had only one (or a small family) trajectory that would "work". Once the situation changes, there may simply be no remedial action the Patriot can take.
 
FWIW Iskander-M has an uplink receiver. It can (in theory) be re-targeted in flight. It also can be commanded to maneuver in order to avoid an intercept. AFAIK there is no evidence that is being done in Ukraine. The maneuvers in  Ukraine are (so far) not "interactive". In theory they can be, so going forward it must be considered. Like many alleged Russian capabilities they may start as out vaporware, but when given motivation and money, they make it work. We might be, once again, forcing them to become competent.

I presume the Iskandar's Mobile launch platform makes it very hard to find and destroy before they launch.

Very true. It was true of SCUDS back in 1990s and Russia has developed a much better TEL for the Iskander-M that Iraq had back then. It can be considered an exact analog of a HIMARS firing its two PrSM.

It seems like Ukraine's best option is to continue launching as many drones as possible targeting Russian manufacturing and production facilities, particularly Gas, Oil and Weapons Technology.  Maybe if they can make the war too expensive Putin may actually have to consider a cease fire.

I doubt the expense will be the issue. If Russia finally does give up, it will be something else that pushes them over the edge. More sanctions might do that. However, Ukraine has to continue doing what it can. Just like Russia's SRBMs aren't going to drive Ukraine out of the war, Ukraine's drone strikes on Russian manufacturing and production won't drive Russia out either. Neither exist at the required scale to do that. However, both sides will persist.

[Goose]

I agree that there is no way to just play defense and win.  I think Russia assumed that its "offense" would so over power Ukraine's defense early on that the war was over before it started.  Three and half years later we know that didn't work.  Ukraine has shown if you are smart and creative you can find new ways to do old things that changes everyone's thinking and forces the other side to rethink their plans.

For certain Russia (and virtually everybody else) expected Ukraine to collapse very quickly. At that point neither Russia nor Ukraine was thinking in terms of an Iskander vs Patriot battle going on for even weeks, let alone years :-). Ukraine had no Patriots at that point. Ukraine has indeed shown an ability to adapt to a very unique situation. While all wars are "unique" in some aspects, the Ukraine ware is totally unlike anything previously observed. Ukraine was fortunate to be attacked by a country that had no effective military (or political except for Putin) leadership and no trained, motivated military force that was prepared to fight Ukraine. This is an almost unheard of event in history. That gave Ukraine the precious gift of time. "Ask anything of me but time". Ukraine also had allies that gave technology to Ukraine that Ukraine could never afforded on their own nor been able to quickly produce. Ukraine has made good use of their opportunities and is holding on by cleverly Macgyvering together an effective military force from piles of differing components. It is however highly improbable such a scenario will play out in the future. For that reason, IMO one has to be very, very careful generalizing from events in Ukraine to future conflicts.

From what I have read, the Patriot sometimes has a hard time intercepting Iskandar missiles.  Do they still have any old S300 systems that might work?

S-300s and S-400s would undoubtedly fare even worse against a modern Iskander-M. The Iskander-M always was "advertised" to have certain anti-interception enhancements over a simple "ballistic" missile. A missile following a ballistic trajectory uses its rocket engine(s) to reach a certain altitude and then falls on its target. Once the engines burn out, the trajectory of the ballistic missile is completely mathematically predictable unless the missile can maneuver. Unlike almost all previous SRBMs the Iskander-M can maneuver, at least to some degree. The forces involved when a missile is falling out of the sky at Mach 5+ are such that no "sharp turns" are possible but tweaks are.
 
The Iskander-M was always known to have depressed trajectory capability. The purpose of that was to trade off some range in exchange for reducing the response time available for the ABM. This has been a Russian specialty going back to the 1970s. Soviet submarines in the Sea of Cortez anybody :-). Patriot doesn't have to do anything "special" to deal with it. The continuously updated tracking solution will work fine when the SRBM does become visible. The Iskander-M also has other defensive capabilities. Supposedly it can use a jammer to jam the radar of the ABM. AFAIK we haven't heard about that happening in Ukraine. The Iskander-M can be programmed to maneuver slightly (subject to g loading) at predetermined points in its trajectory. It is very probable the Patriot tracking algorithms used in Ukraine are not designed to accommodate such maneuvers. A ballistic trajectory is assumed. In some cases better tracking algorithms may be available but not enabled for use in Ukraine. That situation may persist.
 
It must also be recognized that the Patriot (like the Iskander-M) has a kinetic energy budget and g loading limitations. The Patriot may have committed itself to an intercept at a certain place and time. If the Iskander-M maneuvers it is entirely possible the Patriot has no feasible response. The Iskander-M may beat it to the "new" target and there is no answer. This situation becomes more likely as the Patriot is asked to cover a larger footprint. As a point defense system Patriot can depend on the fact the incoming missile must eventually come toward the Patriot. As an area defense weapon that is not true. The Patriot might have had only one (or a small family) trajectory that would "work". Once the situation changes, there may simply be no remedial action the Patriot can take.
 
FWIW Iskander-M has an uplink receiver. It can (in theory) be re-targeted in flight. It also can be commanded to maneuver in order to avoid an intercept. AFAIK there is no evidence that is being done in Ukraine. The maneuvers in  Ukraine are (so far) not "interactive". In theory they can be, so going forward it must be considered. Like many alleged Russian capabilities they may start as out vaporware, but when given motivation and money, they make it work. We might be, once again, forcing them to become competent.

I presume the Iskandar's Mobile launch platform makes it very hard to find and destroy before they launch.

Very true. It was true of SCUDS back in 1990s and Russia has developed a much better TEL for the Iskander-M that Iraq had back then. It can be considered an exact analog of a HIMARS firing its two PrSM.

It seems like Ukraine's best option is to continue launching as many drones as possible targeting Russian manufacturing and production facilities, particularly Gas, Oil and Weapons Technology.  Maybe if they can make the war too expensive Putin may actually have to consider a cease fire.

I doubt the expense will be the issue. If Russia finally does give up, it will be something else that pushes them over the edge. More sanctions might do that. However, Ukraine has to continue doing what it can. Just like Russia's SRBMs aren't going to drive Ukraine out of the war, Ukraine's drone strikes on Russian manufacturing and production won't drive Russia out either. Neither exist at the required scale to do that. However, both sides will persist.