The Government should set out a "realistic vision" of the UK's place in the world and give a clearer indication of the circumstances in which the armed forces could be committed to military interventions, MPs have recommended.
The cross-party Defence Select Committee said the Afghanistan and Iraq conflicts meant there was a "current lack of appetite" for military operations but the MPs warned that choosing not to intervene in some crises could have implications for the UK which are as profound as the decision to commit troops.
The MPs suggested Russia may have felt empowered to intervene in Ukraine because the UK and other countries had failed to act in Georgia or Syria.
In its report the committee said: "Witnesses have suggested that non-intervention could have wider global implications than merely in the current area of concern.
"In this regard, non-intervention can be related closely to a failure of deterrence, for whilst the capability to intervene might exist, the lack of will to intervene undermines the ability to deter.
"For example, the question arises whether the decision not to intervene in Georgia or Syria might have encouraged the current Russian action in the Ukraine."
The MPs said: " We understand and acknowledge the current lack of appetite for military operations given the experiences and tensions of the past decade for operations in countries such as Afghanistan and Iraq.
"However, it is also necessary to understand and acknowledge that there are consequences to decisions by the UK and the international community not to intervene in humanitarian or non-humanitarian situations.
"Non-intervention decisions have implications for the UK's place in the world and its influence which are as profound as a decision to undertake an intervention operation.
"Decisions not to intervene could have wide global implications for efforts to deter hostile actions by other states or non-state actors."
The report questioned ministers' assertions that the UK's influence had not been affected by the squeeze on defence spending.
"We remain concerned about the lack of realism in the Government's assertion that there will be no shrinkage of UK influence when resources are still being reduced.
"We call on the Government to set out in the next National Security Strategy (NSS) whether it still maintains this assertion and, if so, how it could be achieved."
The report says the Government must "articulate a realistic vision of the UK's place in the world, its level of strategic influence and the way the world is changing as well as the identification and prioritisation of the risks to it".
The MPs added: "The next Defence and Security Review (SDSR) should then translate this vision into defence planning assumptions and the development of the appropriate force structure. This would assist more strategic decisions on why, when and how to intervene."
The next NSS and Strategic Defence and Security Review are due in 2015 and the MPs said ministers should set out more clearly the triggers for intervention.
The last NSS in 2010 indicated that the main threat was from international terrorism and "non-state actors".
The MPs agreed those threats remained but called for the next NSS to give " due weight to the likelihood of a return to an increased threat of state versus state conflict" and for the SDSR to ensure force levels able to deal with that possibility.
The committee also urged ministers to clarify the role of Parliament in making decisions about military intervention, following the Commons vote on Syria.
"We do not consider it appropriate for the Government to wait until the next possible military deployment to resolve this issue," the MPs said.
Committee chairman James Arbuthnot said: "The British people are suspicious of the motivation for deploying troops to certain situations but not others.
"We need to see, in the next Defence and Security Review, a definition of the circumstances in which the UK might intervene in future and the legal basis for such interventions in order to ensure a successful outcome and full public support. The Government also needs to be more forthright in stating the consequences of non-intervention when it decides to intervene."
A Government spokesman said: "The decision to use UK armed forces overseas is among the most significant a government can make.
"That's why the Government has stated that it will observe the existing convention that says the House of Commons should have the opportunity to debate before UK troops are committed to conflict, except in cases where the urgency of the action required makes this impossible.
"Military intervention as a course of action can of course be contentious and contested but the Government is clear that it remains an important last resort when all other means of dealing with threats have been exhausted.
"The Government is committed to a strong role for the UK on the world stage and maintains a clear strategy on security informed by regular Strategic Defence and Security Reviews and a National Security Strategy."