1. Let says attack done thru east part of island, thru sea with at least on par with Singaporean Navy orbat but better combat support ship such as Oiler, supply and replenish ship.
2. Just put as world conflict between western oriented nation (led by NATO) against anti-western nation.
3. Just put the campaign taken about a month, which can be justified as a time before major Singaporean alied reinforcement arrived.
4. The attack only involving Singapore alone, with Malaysian & Indonesian in neutral stand.
As Todjaeger suggested, we can discuss the capabilities of the naval force needed to invade Singapore Island. To begin this discussion, perhaps we should list out the forces in Singapore, so as to establish the type and capabilities of the navy invasion force.
From this list of the relevant capabilities of the RSAF and the RSN (to repel a naval invasion force) alone, it would become clear why Feanor said you can count the navies who can take on Singapore with one hand. This list below is not accurate and is compiled mainly from Wikipedia and various other sources. However, it would be sufficient to provide us with a basis to discuss.
1. RSAF's Naval Strike Capabilities
(i) Harpoon Capable Combat Aircraft
- 62 F-16C/Ds (with 24 F-15SGs on order)
(ii) Force Multipliers
-4 E-2C Hawkeye AWACs (with 4 G550 on order)
-4 KC-135R Tankers
-5 Fokker 50 MPA (Harpoon armed)
-1 converted C-130 for SIGINT
(iii) Attack Helicopters
- 20 AH-64D Apache Longbows
(iv) Air force Munitions
- AIM-9J/P/P-3/M/S Sidewinder
- AIM-7M Sparrow
- AIM-7P-5 Mk 58 Sparrow
- AGM-65G/A?/D? Maverick
- AGM-114K-3 Hellfire
- Hydra 70 rockets
- Mk-82/84 bombs incl with BSU-49/B retarding fins
(v) Integrated Air Defence Systems
- Oerlikon Gun
(vi) 4 Main Air Bases with 11 runways with hardened facilities
- Changi Air Base
- Paya Lebar Air Base
- Sembawang Air Base
- Tengah Air Base
2. RSN's Capabilities
(i) First Flotilla (RSN's strike arm)
-6 Formidable Class Frigates (organic seahawks on order)
-6 Victory Class Corvettes
-12 Fearless Class Patrol Vessels
-4 Sjoormen Submarines (also known as the Challenger class)
-2 Vastergotland Submarines, which are AIP equipped submarines (on order)
(ii) Naval Munitions
- Harpoon AGM-84D
- Black Shark Torpedoes, A244s Torpedoes, Type 617 Torpedoes, Type 43 Torpedoes
- Barak I
- Aster 15/30
(iii) 2 Main Naval Bases
- Changi Naval Base
- Tuas Naval Base
3. Singapore Army's Capabilities
3 Combined Arms Divisions, a rapid deployment Guards division, plus 1PDF and 2PDF (each PDF is a division sized force for Singapore Island Defence)
(i) Each of Singapore's 3 combined arms divisions is offensively orientated, with their own organic armour, artillery and mobile air defence elements. This includes Leopard 2A4 MBTs, AMX-13SM1 light tanks and amoured infantry (carried in either Bionix IIs or M113 Ultras). The Guards Division is heli-mobile.
(ii) These armoured elements are supported by the Super Rapid 120MM Mortar mounted on a Bronco, the 155mm/39 calibre Primus SPH, artillery hunting radar, Apache helicopters and UAVs. These support elements have the ability to direct precision fire (from artillery and the air force) and also the ability to gather intelligence (via UAVs and other ground based intelligence sensors) to enable integrated strike operations by both aircraft and artillery.
4. SIGINT & Electronic Warfare Capabilities
Main Combat weapons of the Singapore army:
- Leopard 2A4 (~132) (newly acquired)
- AMX-13SM1 Light Tanks (~350)
- AMX-10PAC90 and other variants (~44)
- M113-A2 ULTRA (Upgraded with 25mm Bushmaster or 40/50 OWS) (~700)
- M-728 CET (Combat Engineers' Tractors) (unknown number)
- M-60AVLB, Bionix AVLB (unknown number)
- Bionix II Versions (unknown number) (upgraded)
- Bronco ATTC Armoured Carrier (~600)
- HIMARS MLRS system (on order)
- FH-2000 155mm/52-calibre Howitzer (~54)
- Pegasus 155mm/39-calibre heli-portable Howitzer (unknown number)
- Primus 155mm/39-calibre Automated Self Propelled Howitzer (~54)
- 120mm Super-Rapid Mortar (unknown number)
- ARTHUR, AN/TPQ-36 and AN/TPQ-37 Firefinder radars (unknown number)
- CIS-50 Heavy Machine Gun
- FN GPMG 7.62mm Machine Gun
- Ultimax 5.56mm Machine Gun
- M-203 40mm Grenade Launcher
- SAR-21 5.56mm Rifle
- CIS (Chartered Industries of Singapore) 40mm Automatic GL
- SPIKE ATGM
- MATADOR LAW
- 84mm Recoiless Guns
According to Desmond Ball, "some of Singapore's SIGINT capabilities... are amongst the most advanced... [including] HF DF/ocean surveillance information... and the most advanced electronic warfare capability in Southeast Asia."
5. So guys, how do you want to proceed from here?