The Commons Defence Committee, which examines the spending and policy of the defence ministry, said nuclear capacity, tanks, warships and aircrafts were needed to deter Russian President Vladimir Putin.
"The world is more dangerous and unstable than at any time since the end of the Cold War," the report said, referring to Russia's annexation of Crimea and seizure of territory by Islamic State and Boko Haram militants.
"But the UK's current defence assumptions are not sufficient for this changed environment... The UK must rebuild its conventional capacities eroded since the Cold War."
The committee said it would be necessary for Britain to stick to its NATO commitment to spend two percent of GDP on defence, but that this would "not be sufficient".
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"It is vital to rethink the fundamental assumptions of our defence planning, if we are to help arrest the descent into chaos, which threatens to spread from the Western Mediterranean to the Black Sea," the report said.
NATO's newly announced "very high readiness joint taskforce" could deploy 5,000 troops in 48 hours, but would not be ready until 2016, the report said.
The report said it was difficult to mobilise "critical mass" in the air as Britain's Royal Air Force had been cut to seven squadrons from 33, while the Royal Navy's frigates and destroyers fleet had more than halved since 1990.
However, Defence Secretary Michael Fallon dismissed the report, saying the Conservative-led government of David Cameron had plugged a "black hole" in the defence budget.
"We are the US's largest partner in the coalition air effort against Isil (Islamic State) - bearing more of the load in terms of strikes in Iraq than we played in either of the Gulf wars.