Gwent Police say they are "satisfied" with the major security operation at the two-day EU foreign ministers' meeting in Newport.
More than 1,500 police and security officers were involved in the event at the Celtic Manor Resort.
Police made two arrests before the meeting of all 25 EU foreign ministers.
Gwent assistant chief constable Bill Horne said he was "immensely proud of those who ensured the security of this event".
The ministers were joined on Friday by the foreign minister of Turkey, which wants to join the EU.
Two demonstrators wearing Jack Straw masks were arrested by police shortly before the meeting began on Thursday.
The 41-year-old man and woman aged 40 were later released without charge.
The UK hosted the meeting - which happens every six months - as part of its year-long presidency of the EU.
The two-day meeting presented the biggest security challenge ever seen in Wales, as a heightened state of alert continues across the UK after the July London bombings.
Foreign ministers assemble for a formal photo at the end of the meeting
Discussions included further EU expansion with the Turkish foreign minister joining talks on Friday.
Several countries have threatened to block the talks because of Turkey's refusal to recognise Cyprus.
But Foreign Secretary Jack Straw said he was confident the negotiations will go ahead.
"As ever when you are facing contingencies, it is unwise to say you are certain, but I am reasonably confident," he said.
Steel barriers protected the roads, and extra fencing sealed the grounds, which stretch over a large area of the five-star hotel - which will host the Ryder Cup in 2010 and staged a celebrity Europe v USA tournament last weekend.
All leave was cancelled for Gwent Police officers, who were joined by colleagues from more than 30 other UK forces.
Mr Horne added: "This event has shown that Gwent can host such high profile events. Whilst the security of the summit was assured, lawful protest was facilitated and thankfully only two arrests were necessary".
A week ago, three men were arrested nearby and released without charge under the Terrorism Act after videoing the area.
The meeting - sometimes known as the Gymnich after the German castle where it was first held in 1974 - got under way with a reception co-hosted by Mr Straw and Welsh First Minister Rhodri Morgan.
Other issues included security and defence policy, and development and trade relations with non-EU countries.
Ministers also attempted to reach a common position on Iran and nuclear development before United Nations inspectors report next weekend.
Mr Straw said: "Nobody is proposing military action in regard of Iran. This is an issue that needs to be resolved, and can only be resolved by diplomatic means".