By Anthony Boadle
BOGOTA (Reuters) - Colombia's ex-president Alvaro Uribe is fuming about the direction his successor is taking.
And he's letting everyone know tweet-by-tweet.
Snide messages to his 470,000-plus Twitter followers are keeping Uribe in the limelight to the discomfort of current President Juan Manuel Santos, Uribe's former defense minister.
The microblogging feud, ironically, is helping Santos break with his past in violence-ridden Colombia and forge his own path as leader of a booming mineral-rich economy.
Uribe has railed in particular at Santos' flagship legislation that provides reparations to victims of Colombia's armed conflict and the restoration of lands seized from peasants by right-wing paramilitaries and landowners.
The former president, whose U.S.-backed crackdown on leftists guerrillas is credited with making Colombia a safer place, sees the law as a concession to the guerrillas.
"Churchill: appeasement of terrorists makes them grow," he tweeted on May 23 from London, paraphrasing Britain's wartime Conservative leader.
"Fighting terrorism is not everyone's piece of cake, but it benefits everyone. Let's not retreat," he tweeted on Thursday.
After leading Colombia for eight years, Uribe is having a hard time adjusting to life out of power, says Michael Shifter, head of the Inter-American Dialogue think tank in Washington.
"He's not content to remain silent and just be a spectator. He wants to be an actor and found his vehicle through Twitter," Shifter said.
So far it has been a one-sided Twitter war, because Santos has avoided a public rift and only sent respectful tweets that recognize he is building on Uribe's achievements in turning around Colombia, now a booming oil and mining economy.
But Santos recently vented his frustration, tweeting that he would not be going around "bothering the incumbent president" when he leaves office. He then later played the comment down.
CORRUPTION, WIRETAP PROBES
Behind the sniping lie deep political, social and cultural differences between Santos, a quintessential representative of Colombia's urban elite, and Uribe, the son of a conservative cattle rancher who was murdered by guerrillas.
Santos was elected last year to continue Uribe's policies and rode in on his wide popularity. But within hours of taking office in August, Santos showed he would be his own man.
He restored relations with Uribe's sworn enemy, neighboring Venezuela's leftist President Hugo Chavez. That angered Uribe who maintains Chavez is still harboring Colombian guerrillas.
Santos named Uribe opponents to his cabinet from the Liberal Party he used to belong to. They have dug up cases of corruption during the Uribe administration, such as a scandal over the misuse of agricultural subsidies.
Uribe himself is under investigation by a congressional committee for his possible involvement in illegal wiretapping of government opponents, judges and human rights workers.
"This is a major split. What is happening is that the pendulum is swinging back to the center and Santos is recovering his personal political vocation," said Humberto De la Calle, a former vice president of Colombia.
Santos and Uribe will not fall out publicly before local elections in October because both want to keep Uribe's U Party together until then, but after the vote a permanent and public rupture is on the cards, De la Calle said.
Burying the hatchet with Chavez has helped end Colombia's diplomatic isolation under Uribe, who was Washington's main ally in South America, and will allow Colombian businesses to recover billions of dollars in lost trade with Venezuela.
It has also paid off for Colombian security since Chavez has begun extraditing guerrillas captured in Venezuela.
Many liked Uribe's personal style of governing, but feel Santos is doing a better job of uniting the country.
Uribe, however, still has a large following, and though he cannot run again for president, the question is, what will be his political future?
"Uribe is a political animal and he is looking for his place," said Shifter. "His poll numbers are still very high. Santos has got to be careful."
(Editing by Jack Kimball, Andrew Cawthorne and Vicki Allen)