Growing fears about the specter of terrorism in Europe and the West are lending themselves to a sense of trans-Atlantic solidarity as the United States President Barack Obama and British Prime Minister David Cameron meet at the White House on Thursday.Close and easy partners, Obama and Cameron have long touted their congenial relationship as a sign of the strong alliance between the U.S. and the U.K. During two days of meetings in Washington, the two are aiming to promote economic growth and global trade even as trickier issues like rising extremism in Europe and cybersecurity take over much of the agenda. In conjunction with the visit, the two leaders are announcing plans to hold joint cyber "war games," starting later this year with a mock attack on banks.Their meeting comes as both the U.S. and Europe are on edge over last week's terrorist attacks in France, where 17 people were slain in attacks spurred by a satirical newspaper's caricatures of the Prophet Muhammad."The terrorists know only how to destroy, but together we can do something infinitely more powerful: build security, strengthen justice and advance peace," Obama and Cameron wrote in The Times of London in a joint editorial ahead of their visit. "The United States and Britain will continue to work closely with all those who believe in peace and tolerance."Yet, the issue of cybersecurity, freshly relevant in the wake of a hack attack on Sony blamed on North Korea, threatened to test the ability of the two leaders to display a united front.On the related issue of encryption, Cameron was coming to the White House with a request in hand. Cameron has said he plans to ask Obama to press U.S. technology companies like Google and Facebook to allow governments to snoop on encrypted communications. Such notions hit a nerve in the U.S., where Obama was forced to order changes to U.S. intelligence collection practices after widespread outrage at revelations that the NSA was scooping up phone records of millions of Americans. Disclosures by former NSA systems analyst Edward Snowden also showed that several U.S. Internet businesses identified were giving NSA access to customer data."I think our British counterparts would agree that it is imperative that we properly balance the need for government, intelligence agencies and national security agencies to access to certain kinds of information to try to protect their citizens," White House spokesman Josh Earnest said.