If you think the beef between Katy Perry and Taylor Swift got heated this week, wait until you hear about the pope and the president.
President Donald Trump met with Pope Francis, the head of the Catholic Church, in the Vatican Wednesday, as part of the president's first foreign tour. It was a typically pleasant, diplomatic photo op, where the leaders had a private meeting and exchanged gifts. But the two have a rocky past, with the pope lobbing thinly-veiled criticisms at Trump during his campaign and after his election, and Trump reacting with ire.
Their meeting Wednesday was no different, with the pope sending a clear message through his choice of gifts, which included a medal of peace and a 38,000-word essay on climate change and the environment. Trump has a record of dismantling environmental regulations and giving top jobs in his cabinet to climate-change-denying officials.
The pope's encyclical (a formal writing), Laudato Si, is a sweeping call-to-action for world leaders to put aside politics and focus on the need to preserve and care for our environment. He penned it back in 2015, but decided to include it among his gifts to the president Wednesday, which also included encyclicals on family life and the gospel. Pope Francis also presented President Trump with a medallion emblazoned with an olive tree, a symbol of peace, and a signed copy of his World Day of Peace speech.
"We can use peace," Trump said in response.
Trump gave the pope a collection of books by Martin Luther King Jr. Exchanging gifts is a tradition whenever an American president meets with the pope. In past visits,the pope gave President Barack Obama medallions and a copy of his encyclical on the gospel, so handing over writing isn't an unusual gesture. But the pope and President Trump's past exchanges imbued the gifts with more meaning.
Read more: The Climate Change Deniers in Congress
When asked his thoughts about Trump's campaign in 2016, Pope Francis told reporters that "a person who thinks only about building walls, wherever they may be, and not building bridges, is not Christian. This is not the gospel."
Trump responded by criticizing the pope, saying "No leader, especially a religious leader, should have the right to question another man's religion or faith."
"If and when the Vatican is attacked by ISIS, which as everyone knows is ISIS's ultimate trophy, I can promise you that the pope would have only wished and prayed that Donald Trump would have been president," Trump said.
Things haven't been much sunnier since Trump's election win. In February, during a weekly general audience to the Vatican, the pope called on all Christians "to not raise walls but bridges, to not respond to evil with evil, to overcome evil with good."
He went on, making comments that many interpreted as thinly-veiled references to President Trump's plans to have Mexico pay for a border wall with the U.S.
"A Christian can never say: 'I'll make you pay for that,'" the pope said. "Never! That is not a Christian gesture. An offense is overcome with forgiveness, by living in peace with everyone."
Subscribe to Science Solved It , Motherboard's new show about the greatest mysteries that were solved by science.