President Obama was assassinated during his visit to Pakistan by a Taliban gunman in 2011. When President Asif Ali Zardari rejected President Biden's request for collaboration in Pakistan of representatives of the US Government and troops for the suppression of the influence of Taliban; US troops from Afghanistan "entered" Islamabad to search for the gunman.
The PPP government was ousted in an allegedly US-sponsored military coup led by General Ashfaq Parvez Kayani due to "corruption", the "secret protection of bin Laden before his death" and "collaboration with Taliban". Following the death sentence of the once extremely unpopular President Zardari later that year, huge anti-Kayani and anti-US protests took place across Pakistan. Under the pressure of Biden, elections were held in 2012 but were considered heavily rigged in favor of the Kayani regime, leading to the anti-government riots across the country. Kayani was then assassinated by the Taliban, and pro-Taliban elements in the ISI took over the government, leading to the bloody hell US invasion of Pakistan.
President Biden was re-elected in 2012 in a landslide with 50% of the popular vote against 39% for Mitt Romney and 10% for the Peace ticket of Ron Paul and Dennis Kucinich. Despite that, Republicans retained the Congress by a two-seat majority, with Eric Cantor as the new Speaker.
What if Taliban did not attempt or could not succeed in killing President Obama in 2011? Would the United States have focused more on the economy? Is it possible that Alexis Tsipras, who refused to leave the Eurozone given that "there is no mechanism to withdraw", would not have become Prime Minister of Greece in such a case? Perhaps Mohammad Morsi would not have been elected President, in the absence of the US invasion of Pakistan?