Depends what kind of weapons the enemy has got.

You have to consider the Star Wars defense system that both Reagan and GW Bush desired to build a fortification and a very stupid one at that. By the time something like that would be operational, it is/was inevitable that a potential enemy out there would have something to either fool it or counter it. Homo sapiens are generally to clever to let a fortification stand in their way for too long. Look at the history of conquests to find many examples of humans outsmarting the hunkered down opponents as examples.

Is it a good idea to build fortresses and walls to hide behind then the enemy strikes rather than making sure your army is stronger than his?

it would seen better to me to have some walls and fotresses or whatever are their modern equivalents to delay and damage the enemy while the army is pumped back in full form.

Any general out there?

I think that applies to modern times as well. Look at World War I. One could think of trench warfare as a form of "walled" combat. That did not work out well for either side. Look at the Maginot line the French constructed to keep out Germany. When Germany invaded, the Maginot line could not withstand airborne assault and fell relatively easily? and that was arguably the biggest defensive wall of modern times. Same could be said for the Berlin wall as well. So walls never really work. Good idea though, but all a wall shows is that the enemy is inflexible and susceptible to a fixed positions. Modern warfare is fluid and asymmetric, a job to which walls are ill-suited.

But I think that even you would agree with this analysis though. You say that a wall would merely delay or damage the enemy, but not completely stop it. But don't get me wrong, there are still walls which are effective. Surveillance walls and buffer zones which are essentially nothing yet function just as well as a physical wall. Heck, people started going underground in response to nuclear weapons and such, and now look. Thermobarric weapons and bunker busters make that direction impossible to defend.

In response to the first part of your 3rd post, even nuclear missiles have an achiles heel? the missile defense network. But even before that, during the 50's the US had an invisible wall of constantly deployed bombers which would retaliate or attack in a matter of hours. The US also had the NIKE defense system, which would detect incoming Russian bombers and launch a nuclear missile into the air which would detonate in the middle of the bomber group? and incidentally above American soil as well.

In response to your hypothetical medieval warfare question in post 3, that is a completely different story. Medieval warfare is tricky in the fact that it was severely regressed on all sides. The best weapon the attacking force could use against any defender is the deadliest weapon of them all?. Time. Siege is very lethal. You could die from hunger and disease easily. But history shows that there were mixed results. Sieges could be lifted by relief forces, but that would assume an "invisible wall" of alliances and deterrence's.

Star wars and asymmetry reminds me of something. I don't know if you remember a year or so ago about the lightly discussed in the media (yet huge within the political sphere) matter to do with satellite killer missiles. China shot down an old satellite of theirs. Two weeks later, the US shot down one of theirs because of "dangerous benzene gas" in its fuel tank. China in turn just developed a new nuclear capable missile which can achieve mach 10. I bet you anything something the US will come out or make known about a counter to that threat. To tell the truth, maybe war happens when there is a lack of counter deterrences.

You're absolutely right, though this need not be solely for when an army is not at full strength. The goal of a war is always to eliminate the enemy's ability to continue fighting -- once that's achieved, strategic and territorial aims are far less costly to pursue. So even in a generally offensive campaign, a defensive position can be tactically very advantageous.

Heh, no general but I've read some books

So suppose this statement... "A wall merely shows the inflexibility of an opponent, and if anything provides more of a target than a defense." Would anyone agree with this statement?

"can the common and obvious conception of a wall hold multiple conceptions of the same concept?" We have "firewalls" after all. Is it any less defensive.

So suppose this statement... "A wall merely shows the inflexibility of an opponent, and if anything provides more of a target than a defense." Would anyone agree with this statement? Would it be an issue of historical context? When I say that, I mean does a wall meant to defend a position during the middle ages differ from a wall meant to defend a position during the the Vietnam war or world war II.

It is in that last question that I raise the issue (and definition) of a wall. walls differ in size, height, etc. But I think modern times call for different conceptions of the term "wall," especially in offensive and defensive terms. Take firing positions and "hill" in Vietnam. Very rarely is there a wall erected to protect a position, however, the concept of a no-mans land of clearing functions just as well. That goes back even to the analogy of trench warfare during world war II. Same word, different conception.

So maybe the question is then... "can the common and obvious conception of a wall hold multiple conceptions of the same concept?" We have "firewalls" after all. Is it any less defensive.

also, I am a big fan of RTS games as well. By the way, if you are considering Total War: Empire... it is a phenomenal game and do not get it. The game crashes like crazy.

I loved strategy games when I was a kid, especially Turning Point: Stalingrad. I haven't ever found a computer strategy game that was even remotely as good as the board games from Avalon Hill and Victory Games. They're all too focused on graphics and on real time action, rather than strategy.