Bertie hasn't been the only taoiseach we've had. The current situation in the Air Corp, and the Defence Forces as a whole, is due to constant neglect by every government that's been in power.
Defence has only been paid attention to in times of dire need, such as the Civil War, the Emergency and the Troubles. Apart from those instances, the government of the day ignored the issue. This has always been the case, it is not particular to Bertie or this government.
The argument could be made that, in relation to defence, the current government failed to spend the required money when they had it. However, I doubt any other political party would have done any better. There's also no point in bringing the National Stadium into the argument. The public wouldn't have accepted spending money on defence any quicker than spending money on that white elephant.