I doubt any country will be eager to adopt Bitcoins as their official currency when any counter-party can effectively take control of blockchain at their leisure with insignificant investment in comparison to their running budgets .

...what?

I thought we had more processing power combined than the latest super computer?
A person in the guinness book of world records thread last week said something about this, I might be wrong, I have to look through that thread again.
So don't quote me on it, but from what I recall China was operating the latest one.


I don't honestly think they are ready for Bitcoin, even though if somehow they did, it would certainly pick up their economy.

Another point, countries like to have monopoly on their money, they won't go with idea of finite money supply, not any time soon

With significant network power they could rewrite blockchain and deny your transactions/coins as invalid, etc. look up >50% hash rate vulnerability.


I'm saying if a country decides to adopt Bitcoin in its current stage of development. If such country has enemies wishing to destabilize it in any possible way, with insignificant investment they could effectively corrupt their newly acquired official Bitcoin currency.  If a country adopting bitcoins invests in its own processing power to back up network, then it could become a new warfare who could out-hash the enemy.  Much  cheaper than building/supporting fleet of stealth bombers/fighters/missiles/etc.

Just a few notes on this situation.


1) Cost is not the limiting factor when it comes to preforming a 51% attack, taking over the block chain is cheap, the problem is getting the cards. As it is the small mining community has already made a major impact in the supply of high end ATI cards, it would take months for any person to get their hands on enough cards to preform a serious attack. Any attempt to acquire such a large number of cards so quickly would throw up red flags all over the place and give the nation under attack ample time to prepare. Any nation attacking Bitcoin would bring it into the eyes of the mainstream media, with more attention comes more miners using already purchased hardware to mine. In attempting to take over the network within any reasonable span of time a nation would bring enough attention to itself to increase the security of the network. The fact is they just dont make the high-end cards fast enough for them to get their hands on even 30,000 within a year.



2) You can not rewrite the block chain with a 51% attack, currently the developers have hard coded points before which the block chain can not be changed, but even if they did not to rewrite the block chain they would have to create a new chain with more proof of work than the main one, that is no easy task, to do so they would need to put more work into their chain than there is work in the current Block chain, this would take years to do (assuming they go all the way back) even if they had significantly more than 51%.



tl;dr Bitcoin is cheap to take over, but money will have a hard time getting those cards made fast enough, re-writing the block chain is currently impossible due to the devs.

Not unless they wanted to go under, graphics cards, like most electronics, have a small profit margin, for a manufacturer to abandon a years profits on a whim and invest in a huge facility and the needed paraphernalia (cases, power supplies, cpu's, ram) would be suicide. And its not like these plants are cheap, they require clean rooms, tons upon tons of valuable rare-earth minerals that are very sensitive to increased demand, building an up to date factory that could pump out the highest end cards would cost in the hundreds of millions easy, especially since they would need to be able to run the whole manufacturing process from silicon to card themselves. Dedicated chips would require expensive and time consuming research and prototyping before they could even begin on the factory (you have to know what your going to build).



If the mining community alone can cause supply issues on the high end cards there is no way they are making even 10million of those. Now i would not doubt for a moment that some of the lower end cards are made on that scale, but the lower end you go costs bloom as you require more power, space, and paraphernalia for the same hashing power.   

No you don't: maybe you need 2  times that for build and mantain it for 6 months. To run a mining farm of  30.000 superpumped 3x6990 rigs (that will do 3X the actual hash power) you need at least 500 full time employees (in 6 month at least 30 million $), (Godaddy has 1500 technical employees for 60.000 servers)
There are energy bill to pay even if is a governative installation (at least 20Million $ for 6 month paying 0,05$/KWh). Add a good 10 million $ of network infrastructure and connectivity (I don't calculate a redundant 10GBit connection to internet assuming a govern can obtain it almost for free) . UPS and backup generator will cost you another 50-60 million $ (we are talkin of a 90MW, a small power plant - a similar one, highly ecological,  built 4-5 years ago costs about 200M$). The cooler must be really efficient to work in a similar environment (one rig produce 1,5KW of heat, like a powerful server with 8CPU and 24 disks. But no server farm hosts 30.000 of that servers for what I know ): at least 30M$.   
The 30.000 rigs wil cost at least 40 million $ (I've considered a 20%-25% less than the wholesaler prices, probably lower than the price you can have buying a bigger stock directly from producers, and with no assembly cost).
Total: 200M$, plus the building, the connectivity, the security (both from hackers and physical assaults). If you're in hurry to build it you can easily double the costs.
Overall if a govern wants  to kill bitcoin, it's still a small investment to do.

As i noted above, its not the cost of the cards thats the problem, its the supply. Fixing the supply problem requires either months of cornering the graphics card market, or the infinitely more expensive option of building your own cards. No amount of money can buy cards that have not been manufactured.