Background on the Saudi Arabian Army:
The army’s main equipment consists of a combination of French- and U.S.-made armored vehicles: 315 M–1A2 Abrams, 290 AMX–30, and 450 M60A3 main battle tanks; 300 reconnaissance vehicles; 570+ AMX–10P and 400 M–2 Bradley armored infantry fighting vehicles; 3,000+ M113 and 100 Al-Fahd armored personnel carriers, produced in Saudi Arabia; 200+ towed artillery pieces; 110 self-propelled artillery pieces; 60 multiple rocket launchers; 400 mortars; 10 surface-to-surface missiles; about 2,000 antitank guided weapons; about 200 rocket launchers; 450 recoilless launchers; 12 attack helicopters; 50+ transport helicopters; and 1,000 surface-to-air missiles.<3> In 2011, the Saudi-Arabian army has furthermore ordered 200+ German Leopard 2A7+ main battle tanks to extend their fleet.http://en.wikipedia.org/wiki/Armed_Forces_of_Saudi_Arabia#ArmyAny Army tried to minimize its weapons, so to ease supply and maintenance problems. Now the M1 and German Leopard were designed to use the same main gun, and the same tools but use different engines and transmissions. If you have one, you continue to buy that model just to keep supply and maintenance problems to a minimum. You do NOT buy a different make and model unless it is a substantial increase in some combat ability (and no such difference exists between the Leopard 2 and the M1) OR you can NOT get what you have when you need it (i.e. can NOT get more M1 this year, maybe next year, but NOT this year, but Leopard 2s can be obtained this year).
That brings us to the issue of "WHY". For putting down internal unrest the 1960s era AMX-30s and M60A3 the Saudi have and good enough to assist infantry to put down internal unrest. Iran had T-72s, but no one is even proposing that Iran can send its Armor Forces into Iraq and then Saudi Arabia, and if the Iranians did do it, the US had the capacity to destroy those Iranian Armor Formations well before there even reach the Iranian-Iraqi border let alone the borders of Saudi Arabia. No one on the borders of Saudi Arabia had the capacity of launching an armor attack on Arabia (Even the Israelis would have a problem given the distances involved, The Israeli Defense Force could do such an attack and the Saudi would have a tough time stopping it, but it would run out of fuel well before it came close to the Arabian Oil fields let alone the Capital of Saudi Arabia).
Thus why 200 plus tanks? They have 315 M1, which is enough to arm five Armor Battalions (A Typical Western Armor Battalion is made of up 54 tanks each, each battalion made up of three tank Companies of 17 tank per Company, each company made up of Three Five tank Platoons plus a Company Headquarters of 2 tanks). The 315 tanks mean Five Battalions of 54 tanks each (Total 2700 Tanks), leaving 45 tanks for other uses including spares. 200 plus tanks can mean Four Battalions of 54 tanks each (Total 216 Tanks). Again WHY four new battalions of Leopard 2 tanks?
Remember the House of Saud is entering its third generation of rule, the First Generations was the original King Saud, who died in 1954. He had numerous sons by numerous wives. As long as his sons ruled (And that has been the case since 1954) peace among the family members have been kept. The problem with most hereditary ruling dynasties is that they survive the first and Second generations, for brothers rarely want to fight brother, even half brothers, but cousins are ready, willing and able to fight for their "Rights" when it comes time for the Grandchildren to rule.
Could it be, that some one thinks King Abdullah's time is up and it is time for the third generation to take over? King Abdullah's strength is in the Saudi Arabian National Guard NOT the Saudi Regular Army and the Saudi Arabian National Guard is a force independent of the rest of the military establishment. The above weapons are NOT weapons of the National Guard, could the Leopard 2s be for the Guard? The Saudi Arabian National Guard has three "Mechanized Battalions" and thus 200 plus tanks would be a good retrofit to strengthens the Guard is respect to the Saudi Army. Given the age of King Abdullah that may be why the rush. The Saudi Arabian National Guard is tied in with the various tribes of Arabia more then is the Saudi Army, so other politics may be involved.
More on King Abdullah and the Saudi Arabian National Guard:
http://www.globalsecurity.org/military/world/gulf/abdullah.htmKing Abdullah seems to have had some recent health issues:
http://en.wikipedia.org/wiki/Abdullah_of_Saudi_Arabia#Succession_to_the_throneNotice former King Fahd was one of seven full brothers (of the same mother and King Saud) who are called the Sudairi Seven and that branch of the House of Saud control the Army of Saudi Arabia.
More on the Sudairi Seven:
http://en.wikipedia.org/wiki/Sudairi_SevenThus who is these Leopard 2 for? The Saudi Arabian National Guard or the Saudi Army? If the Leopard 2s are for the Guard, it could be Adbullah strengthening his family position within the ruling house. If it is for the Army, it may be to make the Sudairi Seven stronger. I doubt it is do to any foreign threat, something is up in Arabia.