In 2156, the United Earth (UE) and her allies, Tellar and Andor, went to war with the Romulan Star Empire. Although tensions had been building for several years and support for a war was widespread on Earth and her colonies, Earth's armed forces were poorly prepared when hostilities actually broke out. At that time, the ships of the UE Stellar Navy (UESN), which had until 5 years earlier been called the UE Space Probe Agency, were mostly poorly armed survey vessels, converted merchantmen of various sizes and configurations, and small attack craft that were incapable of independent interstellar operations. Although converted interstellar cargo ships, such as those of the 400,000-t PIONEER class (CH-29), could carry, by virtue or their great size, substantial firepower, they had never been intended for offensive operations. The most capable ships of the UESN were probably those of the fusion-powered AMARILLO class (CC-33); however, they too were of limited ranged and only four ships had entered service since 2152.
At the start of the war, all belligerent powers used warp-capable ships powered by fusion reactors. Although rarely used for this purpose today, fusion reactors were the sole means of power for the first century of warp flight on Earth (a notable exception are the fusion-powered accessory nacelles mounted on the primary hull of some early NEBULA-class ships). Fusion-powered warp reactors have decided disadvantages when compared with modern matter/antimatter (M/AM) systems. Probably the most serious disadvantage, in tactical terms, is their relatively low efficiency. To form and maintain a warp field, fusion reactors must consume deuterium at extremely high rates, which places two limitations on a ship's capabilities. First, a large percentage (70% or more) of the ship's mass is fuel, which limits nonfuel payload, such as weapons, sensors, and shuttlecraft. Second, the high rate of consumption severely limits range. The first limitation of payload can be partly addressed by scaling up the ship. Since a fixed percentage of a ship's must be fuel and drive system to operate at a given warp speed for a given duration, the nonfuel payload can be increased by increasing the total size of the ship. The second limitation of range must be addressed by frequently refueling at starbases, convoying the ship with tankers, or rendezvousing with tankers en route. Another disadvantage of fusion reactors is their low peak power output, which limits the maximum speed that can be achieved to about warp 2.5, or 15.6 c.
Because of these limitations of range, speed, and payload, fusion-powered ships were unsuited for offensive interstellar operations. For an attack to succeed, it must be made either when and where the enemy is least prepared or with an overwhelming superiority of force. However, the limitations of range meant that attacks across more than 10 light years (ly) of interstellar space could not be accomplished without repeated refueling, which required that ships drop out of warp and risk detection and interception. If possible attack corridors shorter than 10 ly were continuously well defended, all attacks could be probably be discouraged or repelled. Furthermore, the maximum speed of warp 2.5 meant that a journey of 10 ly would take at least 234 days, during which time detection and interception become increasingly likely. If a ship were to carry enough armaments for a powerful attack on enemy ships or ground targets, the fixed percentage of available payload meant that the ship would probably be extremely large and poorly maneuverable at both warp and impulse speeds. Fighter carriers, of course, were impractical within these payload limitations.
When Earth forces were finally given the opportunity to go on the offensive after a Romulan invasion fleet was destroyed at the Battle of Hell's Gate in 2157, the strategies available were severely limited by the poor quality of UE warships. Despite broad popular support for attacks against Romulans planets, the UE and her allies simply did not have ships of sufficient capability and in sufficient number to successfully undertake offensive operations. Instead, ship-to-ship combat most often took the form of long-range missile duels. Opposing ships would cautiously venture out from their bases until long-range sensor contact was made. The ships would then usually close within extreme missile range, fire a volley of missiles, then attempt to evade their opponent's missiles. As a result, many engagements ended without significant damage to either ship. For the UE to undertake offensive operations, a power source enabling more-dynamic warp flight was obviously needed.
With the start of the war in February 2156, the UE War Council decided to make production of a M/AM-powered warships a priority. As a result, 50 trillion new solar dollars per year was dedicated to M/AM reactor development. This investment equalled, as a percentage of gross domestic product, that of the old United States of America for development of the first fission munitions in the mid-20th century. The flight test program was proceeding smoothly when on her 10th flight on April 23, 2156, Little Nell was destroyed by a catastrophic warp core explosion, likely due to spalling or delamination of the inner surface of the M/AM reaction chamber. However, within 6 months a second prototype, Little Nell II, was launched. Ironically, the destruction of Little Nell may have actually accelerated development, as the new SSWR-IIA reactor installed in Little Nell II incorporated numerous improvements ahead of the original development schedule as well as being lighter (25,000 tons) and smaller (2,800 cubic meters). After an accelerated testing program the improved SSWR-IIA reactor was formally certified by the UESN Propulsion Board for installation in naval vessels in March 2157. The first ships to use the new reactor were KRECHET-class cruisers (CCM-1).
In the aftermath of the failed Romulan invasion of October 2157, a call went up throughout UE space for immediate retribution. Citizens of Earth and her colonies now believed that merely defending UE space against the Romulans was no longer sufficient; instead, they felt that Romulan worlds must be directly attacked. However, in 2157 the UESN was not yet able to mount offensive operations. As the outcome of the Romulans' attempted invasion so clearly showed, fusion-powered ships were simply too large, too slow, and had payloads and unrefuelled ranges too small to successfully attack across distances of more than a few light years. In fact, the Romulan invasion fleet had been discovered when two UESN M/AM-powered cruisers followed Romulan tankers attempting to rendezvous for refuelling. These limitations were recognized by the UESN Admiralty, who tried to explain to an increasingly outraged public that destruction of the Romulan homeworld was not a war aim of the UE-Andor-Tellar alliance. The Admiralty had long believed that the mission of the UESN was to defend allied space and had prepared its fleets accordingly. Unless the Romulans were to somehow obtain more powerful warp drives (an extremely unlikely possibility given their frustrated attempts to harness quantum singularities rather than antimatter), the UESN's existing fusion-powered ships supplemented by M/AM-powered ships in limited roles were likely sufficient for defensive actions. However, if the UESN were now ordered to go on the offensive, the necessary changes in equipment, tactics, training, and crew deployment would be extremely costly yet were not guaranteed to achieve the desired affects.
Despite these concerns, UESN engineers continued their work into applications of M/AM power. The first ships to enter service were those of the KRECHET class in May 2157. Reactors subsequently became smaller, allowing a greater variety of ship types to exploit the new power source. New ship classes entering service in the 12 months after the KRECHET class included TORSK-class destroyers (CEM-1), TANNHÄUSER-class heavy cruisers (CHM-55), OLYMPUS MONS-class combat transports (APM-8), REID FLEMING-class deuterium tankers, FARRAGUT-class fleet monitors (FMM-1), POWHATAN-class cruisers, and YORKTOWN-class carriers and MINOTAUR-class fighters, designed for offensive operations. The significantly better performance of even these early M/AM-powered vessels over conventional fusion-powered vessels convinced the Admiralty of the worth of the new reactors. The final years of the war saw the introduction of CONQUEROR-class heavy cruisers (CHM-69) and the first "modern" starships, the COMET class.
The advantage that M/AM ships gave the UE Alliance cannot be overstated. With the higher speeds and greater ranges possible, the UESN could choose when and where to engage the Romulan fleet and could attack too many targets for the Romulans to adequately protect. The sudden appearance of so many M/AM-powered ships of numerous classes and the rapid destruction of their invasion fleet at the Battle of Hell's Gate likely came as a profound shock to the Romulans. According to a Romulan Commander who defected to the Federation in 2268, several members of the Romulan Imperial Fleet's High Command came to believe that the war could not be won. They recognized that the starship technology and industrial capacity of the UE Alliance far surpassed their own. Even if the Romulan Star Empire could somehow resist the expected attacks from the UE alliance and transform the conflict into a war of attrition, the superior industrial capacity and greater population of the UE would mean certain, eventual victory. These officers approached the Praetor to suggest that peace feelers be sent through Vulcan intermediaries. Although they had clearly and correctly assessed the dire situation confronting the Romulans, they were tried and executed for sedition under emergency wartime laws. The war would drag on for a further 3 years with the outcome never in doubt.
Although most other powers had obtained M/AM reactor technology by the turn of the 23rd century, the Romulans were not to do so until their short-lived alliance with the Klingons in the 2260s. The main reason for this delay was that the Romulans had long believed that quantum singularities would ultimately prove a more powerful energy source for warp drives and devoted most of their research to this goal. Indeed, even after trading cloaking devices for M/AM reactors, the Romulans continued their work on quantum singularity-based drives. Precisely when such drives became operational is unknown; the Romulans were still using deriatives of Klingon-designed reactors at the time of the Tomed Incident (2311), but Galaxy-class USS ENTERPRISE (NCC-1701-D) confirmed in 2368 that D'DERIDEX-class Warbirds were so equipped.
2160
The UESN destroys most of the Romulan fleet at the Battle of Cheron. (August)
DAEDALUS class exploratory cruiser enters service. (August)
The Earth-Romulan War ends. (September)
2161
The United Federation of Planets is founded at the Babel Conference, with the newly formed Starfleet as its primary interstellar naval force.
UES DAEDALUS is recommissioned as USS DAEDALUS (NCC-150), the first starship to join Starfleet.
Cheers, Thorgrimm 
