The portfolio of projects undertaken by Giuliani after he left New York City's mayor's office brought Giuliani to foreign countries that could come back to haunt him should he be chosen as the nominee. He is currently described as the frontrunner for the position.
Giuliani also earned millions of dollars in speaking fees from more than 100 groups in 2006 and 2007, including big US banks, oil giants and foreign companies.
One matter should be familiar from his 2008 presidential campaign: a possible link between his former massive law firm, Bracewell Giuliani, and a Venezuelan oil company. The firm represented Citgo Oil, which is a subsidiary of the state-owned oil company in Venezuela.
Giuliani is also likely to be criticized for of his work for the government of Qatar, which hired Giuliani to help with intelligence security. The firm also had offices in the United Arab Emirates and worked on financial deals for other nations in the Middle East like Saudi Arabia, Bahrain and Oman.
Bracewell Giuliani had hundreds of attorneys employed across the US and the world, with foreign contracts spanning the globe and tens of millions of dollars in contract fees. Other work was through another company of his, Giuliani Security.
Those contracts include work combating crime in Mexico City, El Salvador, Colombia, Chile, along with helping political candidates in Ukraine and the Dominican Republic.
Some critics are already seizing on the paper trail. Rand Paul, a Republican opposed to the interventionism supported by Giuliani, deemed them a problem.
"I think it's a bit worrisome -- some of his ties to foreign governments," Paul said. "Because that was a big complaint from many of us about Hillary Clinton and her ties and money she received from foreign governments. So whether or not you have divided loyalty obviously is very important."
During the general election campaign, Giuliani frequently intoned against Clinton's influence-peddling around the world, most of which centered on the charity work by the Clinton Foundation. He called the philanthropy a "racketeering enterprise" and alleged that she turned the State Department into a pay-for-play operation."
Giuliani also slammed Clinton for earning millions of dollars in paid speeches.
But the former New York City mayor earned a net total of $9,195,000 in speaking fees from more than 100 groups in just 2006 and 2007, according to the 2007 personal financial disclosure form he released during his 2008 presidential campaign.
Giuliani earned $60,000 in speaking fees from Shell Oil Products and the same amount from Novartis Pharmaceutical Corporation as well as hundreds of thousands of dollars from big banks including JPMorgan Chase, Lehman Brothers and Credit Suisse.
He also pulled in $200,000 from an Icelandic telecommunications company Siminn and $200,000 from a Polish research group.
The biggest check he earned came from Sage Capital Group, a New York private equity group.