Space Combat in the Alpha Quadrant
Distance is under-represented in space opera
One of the things that you are rarely shown in Star Trek and indeed in most space operas is the vast distances capable of being created with just a few seconds of combat at near light or light speeds. You do not see this during the show mostly due to dramatic license.
For example: The distance to the moon is about 240,000 miles and at light speed this distance is covered in 1.5 seconds. At light speed that would seem very fast, but remember in the time it took for the beam of light (or a phaser or torpedo) to cover that distance, the target in the same time can add that distance in a different direction in the same time.
Despite the fact that pilots and weapon's officers appear to be involved in the combat on Alpha Quadrant ships, the fact of the matter is for weapons to be effective, they are more often than not computer-assisted to allow for the speeds capable of being reached and at the distances involved, humans would barely be able to compensate for the differential between two vessels moving at near-light speeds.
The most effective combat between Alpha Quadrant ships has to take place at ranges less than one light second, because these ranges would be the most effective ranges to use their weapons. Even stranger, that most battles, particularly the ones during the Deep Space Nine series would be less than a few thousand miles apart, basically point blank ranges, making combat particularly messy, destructive and final. Check out the battles during the Dominion War and you will see combat taking place at ranges of 1,500 KM or less.
The species of the Alpha Quadrant would likely use several tiers of countermeasures/defense against attack.
Passive countermeasures - passive countermeasures include technology that prevents ships from being effectively scanned, shield against the ship giving away information about its status or crew complements - this status is operational as soon as a ship goes into Yellow Alert, and is heightened under Red Alert.
Passive defenses - Passive defenses include the armored hulls of most ships, while shields are the primary defense of a starship, their hulls are supertough composite materials capable of being struck by powerful weapons and surviving. Inside ships, isolation fields which compartmentalize the hulls of vessels preventing the loss of crew and atmosphere and allow crew members to continue working in areas that would otherwise be in-hospitable.
Active countermeasures - would be the tactical use of computer sensor systems to scramble torpedo targeting and breaking targeting locks by other ships. Those locks would have to be re-established periodically as computers onboard the target ship, search for opportunity to lock on to other vital areas of the ships.
Active defenses - these would include systems such as point defense phasers, designed to be fired to destroy incoming torpedoes before they can reach their optimal arming and detonation stages. While these would not be effective against other ships, they would be sufficient to destroy the containment of a torpedo rendering it inactive (and non-explosive).
It is likely that each race, depending on its proclivities might have more or less experience with one or more of these types of countermeasure/defense types. For example:
Romulans would likely be strong in countermeasures but weaker in point defenses since they make an effort to know more about enemy ships using spies and they fighting the Klingons would be less likely to meet a photon torpedo in average combat. So their skills at confusing ship targeting systems may be significantly higher.
Klingons will likely spend more on defense and less on their countermeasures since they prefer to enter into straight up fights against the enemy. So their ships likely pack more defense systems, reducing attacks from torpedoes or other small ship combat, since they fight against other Klingons and Romulans who use small ships and the Romulan torpedoes, which are both slow and amazingly powerful. Later Romulan vessels use the same disruptor technology the Klingons use because of their long range and relatively low power requirements.
The Federation may be one of those which will spend equal efforts on sensor countermeasures and defense platforms.
In the same manner modern navies use technology to attack their opponents, such countermeasures would exist in the Alpha Quadrant, even if they did not receive the acclaim that weapon systems get.
Tactical officers would be trained in ways to make their ship less easily struck using the ship's sensor array to confuse the targeting systems of both enemy ships and enemy weapons platforms such as torpedoes more likely to miss.
Considering their devastating yields, it would be in the best interest of the defending ship to force as many high-yield weapons to miss the ship and its shields as possible. Electronic countermeasures would require significantly less power than shields or other point defense technologies.
One of the things that was most effectively shown in the recent new Star Trek (2009) were the phaser-based point defenses which were far better represented than at any time in the past. As a former military person, it was gratifying to see a more realistic display of the layered technologies required for weapon-bearing ships to be effective. Star Trek's space battles always seemed so simple and had none of the complexity modern militaries use in combat today.
When Star Trek, in the form of Starfleet Command video games by Interplay tried to bring their space battles to computerized games, many of the difficulties became more apparent depending on the weapons used and the races involved. The two things to be considered were the optimal ranges of a weapon and the maximum ranges of a weapon.
Optimal ranges deal with where the weapon is likely to be most effective and resistant to countermeasures. Maximum only deals with the possibility of being able to hit the target.
Depending on the weapon, it became a critical issue to find your weapon's sweet spot and keep your ships in yours, while denying your enemy his optimal range. Combat rarely resembled the show with distances being on average further apart than the ranges in the shows would represent.
The famed game Star Fleet Battles displayed how weapons used by Alpha Quadrant races would have made battles against different forces quite variable and again different from what was seen on the screen.