"As an outsider, I feel like the US is the opposite of an "agile" government."

For about every aspect of the US federal government, you're right: http://www.zdnet.com/blog/hardware/us-government-blows-20000...

It's /really/ hard to manage the world's largest GDP effectively. Governmental gridlock tends towards the status quo and institutional inertia is huge. This is Vernon Vinge's 'to scale, you need complexity, but complexity inevitably leads to collapse' theories in action.