The War itself is neither an art nor a lie...
I will not comment on real life wars but will make some comparisons of course in this guide.

When you decide to press the declare war button you should ask yourself some questions at first:

Why I want to achieve in this war?
Can my country sustain it?
How do I plan to end the outcome of it?
Of course above all what kind of war shall I prefer? ...etc.

I just ask myself what type of war I want.

In real life there are many war types but in supreme ruler the basic ones are below:

World Conquest: Very simple conquer whole world not even any small ally wanted suited for spherophobics. (Sphere of influence haters) .

World Conquest with Allied Victory : You will tolerate some dumb AI to share the world with you suited for spherophiles.(Sphere of influence lovers) .

Scorched Earth War : You will destroy or logically scrap an enemy nation for self satisfaction.

Puppet them all : scrap whole world and puppet them for another self satisfaction.

Armageddon : Nuke them all, for hidden sociopaths. SRU has no fallout mechanic so SRU nukes are the cleanest.

and my favourite one : Roleplaying a war game on how could I change the course of history.

In SRU defence is best offence. This would be your main goal till the AI waste all of its main field army. I mean non-garrison units of course. I hate garrison mechanics who likes it by the way :)

After AI starts sending you only AA or ART units you may see easily it is time to begin our beloved part of war -garrison hunting-.

To get the main operational level (Killing blow) we should know AI a bit.

The real Art of War says know enemy and know yourself. In SRU AI DOES:
-Suicide rushes to your beloved trenches or better emplacements
-Good submarine warfare
-Bombarding coastal cities
-Sending some spies mostly with recon mission
-naval invasions if you forget to deactivate ports
-and the best: it will sue for peace
-and many other things as well


but AI DOES NOT:

-build any fortifications even cheapest trenches
-strategical bombing -sea and air-
-storing gas or amno enough for 10 years
-stop sending tanks to cities -no comment on modern Russian army-
-use puppets as cannonfodder
-stop invading non-supplied hexes to be a drill target by your CAS(T. Bombers) or S. Bombers

For endless battles and skirmishes be sure to do before press the declare war button:

-Close -deactivate - undefended ports
-have 7 stack units preferably as battle groups
-have 2 battle lines my favourite 4inf+3tank as frontier troops and 7 art or 5Art+2AA as support line
-if you play with capture victory condition send your command unit way from battle line if you do not roleplay Caesar or Rommel of course
-till modern era prepare 2 capital ship +5 sub offensive flotilla if you play with any naval nation Italy 1936 is my favourite one.

After you press the button:

-do not waste your field army units send them to repairs
-support them reserve battle groups do not put all your eggs in one basket
-play on normal or below speed
-do not attack a second nation - do not get cocky -
-wait for AI waste its army till it begin to beg for peace or send art or aa units to offensive operations
-and of course never allow your minister to take control of your army

When the shooting starts you will witness many info bombardment all around but you should focus on one thing alone: Sustaining the war. To be able to do it you should know at least logistic and supply system of the game.

-Without gas your motorized and mechanized units do not move.
-without military goods they do not shoot at the enemy

To keep the army going : you should check your gas and mil goods regularly, even you have 10 years of stockpile of them you will see them evaporate very quickly.

Newly conquered hexes will not have any supply till midnight - the next day- so slow and a steady progress is more suitable than a blitzkrieg in the game.

If you play with nations with huge landmass, be sure to build necessary supply buildings.

Personally if I began to be fortunate enough a full 7 supply truck 3rd battle line is my ultimate dream for both defensive and offensive operations.

So I try to keep the guide as simple and short possible.
To be clear and self explanatory this is my summary of war game for Italy for 1936.

I have two ways to play Italy lazy way and hard roleplaying way. I will mention them both.

Italy is tutorial faction for WW2 maps. So any player who played tutorial began having a love-hate relationship with her.

She has a nice navy but not par with UK of course and RIP with UK France united navy.

Its is very easy to defend as a boot shaped country as you can just defend north of the country with army and with enough investment of 2 subs per each coastal city you can focus on the offence very quickly.

Before I enter the war, I must keep Italy as neutral as possible as when I become axis aligned UK DOWs me immediately if I play with Sphere System. So I keep avoiding to support Germany or any other axis development. With worse situation namely war with UK before 1939 can be coped with easily in fact.

I build trenches -lazy way- or emplacements on land borders.
Stop wasting my time in Ethiopia and calling back whole troops to home. -lazy way-
Immediately annexing Libya in day 1.
Building 4 research centers and 1 airbase and barrack in Rome.
Taxing the pop to death just 1 % for the last 3 tax types
Resourcing gov expenditures to recommended levels
Max garrisons till I build 5 art 2 inf stacks for each coastal city
Italy is basically one of the worst nation on self sufficiency
Libya has enormous gas fields even so as to sustain a world conquest
Other than Libya I scrap then colonize conquered lands
If I manage to stay neutral till the historic timeline of ww2 I always keep enough expeditionary force in Germany or wait her to collapse to be axis sphere leader if I could
Have enough navy to keep UK later any ally away from Mediterranean.
Then one by one I keep conquering and puppeting whole africa then asia finally americas.

For democratic version of the game France (Ally) or Spain (Neutral) are best alternatives for naval war simulations for navy lovers.