Command & Conquer: Red Alert 3/Allied Strategies

Allies vs Empire
The Allies are a well balanced force in Red Alert 3. A strength of the Allied forces is clearly their air superiority. One strategy is that of the Vindicator rush. With the ability to build these aircraft very early in the game, rushing to build an  airfield as soon as possible and blitzkrieg-ing your enemies is a  sure recipe for a early victory. This is really a when facing the empire as their early anti air defenses are weak at best. This strategy is not as useful against the soviets. This make sure you don't fully neglect land defenses because you never want to leave your base fully undefended. Also make sure your opponent hasn't snuck a nano-core to the sea where he/she starts building a secret navy base that will grow and challenge and haunt you in the future.

Allies vs Soviets
The Soviet advantage lies with their early vehicles, the Terror Drone and the Sickle. The Terror Drone has the ability to cripple your economy for a measly 500 credits, by disabling or destroying your Prospectors. The key to countering this is walling in the path between your refineries and their respective ore nodes. Sickles can be devastating to your infantry. machine guns and the Flea Jump. If you are intending to use infantry, never bunch them up and use the Scatter (X) key when necessary.

It must be noted that air sorties with Vindicators are not an efficient way to deal early-game strikes against a Soviet opponent due to the early availability of Flak Troopers and Bullfrogs.

One strategy that is effective is to put a produce 2 multi-gunners and put an engineer into each of them. These vehicles then become "mobile repair units". Always produce at least 2, not just one, as they can then repair each other. 5 Guardian Tanks, 2 Engineers-Multi-Gunners, 3 Rocket Troops into a Multi-Gunner. This group of 10 can be used to rush an enemy base. The Guardian Tanks will form up front, and take the hits while the repair carts will keep repairing them. (Similar to the Starcraft Terran strategy of Marines+Medics)

Allies vs Both
The Chronosphere can be used as a directly offensive weapon - you can use it to destroy enemy land units by teleporting them into the water, or naval units by teleporting them onto land. Amphibious can be destroyed by teleporting them into buildings.

A highly efficient way to apply pressure on an opponent early in the game is to load a Riptide ACV with 5 Javelin Troopers, or two such Riptides if your economy allows it. The Riptide can handle a few Infantry, while the Javelins can take out buildings and vehicles (remember to watch out for Sickles if facing a Soviet enemy!). Focus on production structures and Ore Refineries. Coupled with 2 or more Multigunner IFVs (possibly with Peacekeepers inside), this force may be enough to cripple the opponent for the remainder of the game. Don't forget to replenish your forces, as necessary.

If the initial strike fails, assess the impact of your attack. If your opponent will take some time to recover, try again. Otherwise, quickly reach Heightened Clearance and use Guardian Tanks in combination with a similar force mentioned above.

As mentioned before, the Allies possess a well balanced force with some exceptional examples. The Peacekeeper is arguably the best "grunt" unit of the three factions, the Hydrofoil is undeniably the best ground-to-air unit, with the added bonus of the weapon jammer. The Mirage Tank, though the weakest Tier 3 tank in the game, is the cheapest, and the easiest to conceal.

Top Secret Protocols
The surgical strike works great on units, but poorly on structures. If the computer repairs its' structures, or against a human opponent, don't waste the surgical strike on a building unless it's already hanging by a thread. It is much more useful taking out an anti-air structure or heavy tank.

The time bomb cannot be placed directly on top of a structure or unit, unlike air strikes or satellite blasts. It is a chronosphere-transported unit itself, and must be placed in the space between buildings and units. It is also vulnerable to being targeted and destroyed by enemy units, so beware of placing it beside an offensive force run by the computer. A human opponent may not react in time to attack with their units, but the computer is pretty good about it.

The Chrono Chasm is both an offensive and defensive power. On one hand, it can be used to stall an attacking force if timed and placed correctly (though, the Cryoshot is more effective for this as you can destroy the frozen units easily). It can also be used to disable your own structures in the most dire emergencies. On the other hand, it can be used to stop the countdown on enemy superweapons, disable closely grouped power plants or a Super Reactor, or to phase out any defensive structures preventing you from disrupting your opponents economy.