The difference is that Bush, 4 months from the end of his presidency, left it for the incoming administration to determine the appropriate response.
Bush had a presidency that manifested a willingness to defend U.S. citizens and national interests throughout his 8 years, starting with invading Afghanistan after 9/11, and making threats and following through in Iraq.
So effective, in fact, that after the Iraq invasion, that Ghaddafi surrendered his nuclear weapons program to U.N. inspectors, rather than risk being next for a U.S. invasion. A nukes program that no one even knew they had!

I would also argue that Bush's response in August 2008 deterred Russia from seizing all of former-soviet Georgia, rather than just the two smaller pro-Russian provinces.

In contrast, Obama surrendered a missile defense shield for Poland and Czech republic and U.S. nuclear missiles, and in return got absolutely nothing from Russia, betraying Poland and the Czechs without even consulting them.
Obama abandoned Mubarek in Egypt, after his 30-plus years as a reliable ally of the United States, and enabled a radical Islamic government to take control of that nation, that endangers both Israeli and U.S. national interests.
Likewise, Obama helped an insurrection in Libya, even though Ghaddafi had been cooperative with the U.S. in recent years, and again allowed a radical Islamic government to take control of Libya as well.
And the flaccid response to the Benghazi attack, which even angered the Libyan government.
As a result, none of our European or middle east allies trust the U.S., at least as long as Obama is in office.

Plus overly rapid retreats from Iraq and Afghanistan, leaving our allies there to stand alone against their enemies. Which is why they have already cut deals that undermine U.S. national interests with the Iranians and the Taliban, respectively.

This is what preceded the Russian invasion of Crimea. If there is a crisis, it is because Obama has invited it.

In sharp contrast to W. Bush, who stood up for U.S. national interests, even when it hurt him in the polls.

Last edited by Wonder Boy; 2014-03-15 11:25 PM. Reason: typos corrected.