Please, let's talk about other anti-double spend things on a separate thread.

On Tue, Jun 17, 2014 at 5:58 PM, Isidor Zeuner <cryptocurrencies@quidecco.de> wrote:
What prevents the following steps from happening:

I linked to Satoshi's post on this earlier, he explains why it works there, assuming people follow the original protocol rules.

Your analysis holds as long as network abandons the original Bitcoin design. Obviously, we hope people won't do that. If everyone decides not to do things how Satoshi laid out then things will break, although whether we have a failure of "Bitcoin" at that point is debatable.