The Indian Navy has had a big week. The reactor in its first indigenous nuclear submarine, the Arihant, went critical on Saturday, and its first indigenous aircraft carrier, theVikrant, was formally unveiled today. It's long been assumed that one of the primary tasks of the rapidly-modernizing service and its expanding fleet is to apply pressure to China's Sea Lanes of Communication (SLOCs) in the event of conflict. 
The Economist suggested a few months ago that "India’s naval advantage might allow it, for example, to impede oil traffic heading for China through the Malacca Strait." David Scott's recent article in theJournal of Strategic Studies, argues that: "In the case of the Malacca Strait … India [has] the ability to block (China’s so-called ‘Malacca Dilemma’) easy Chinese access to the Indian Ocean." Ajai Shukla, a well-informed defense journalist, writes that "analysts agree that the Indian Navy … can shut down the Indian Ocean shipping lanes whenever it chooses," and quotes a retired fleet commander as saying that "a couple of submarines and a fighter squadron at Car Nicobar could easily enforce a declared blockade." India's first official naval doctrine, in 2004, itself boasted that "control of the choke points could be used as a bargaining chip in the international power game."
Raja Menon, a retired Rear Admiral and prominent advocate of seapower in Indian strategic debates, built on these assumptions in a recent op-ed in the Hindu, criticizing the government's decision to invest substantially in raising a new Indian Army strike corps intended for the Chinese border:
Most of all, we appear not to have assessed the Chinese weakness and strengths. Their strength is the huge logistic network that they have built up in Tibet. By creating a one axis strike corps, we have played into their strengths. The Chinese weakness lies in the Indian Ocean, a fact that even Beijing will readily concede. The clash between their political system and economic prosperity requires resources and, increasingly, the Chinese resource pool is Africa, which generates massive sea lines of communication (SLOC) through the Indian Ocean. Today, they are merely SLOCs; tomorrow they will be the Chinese Jugular. Beijing’s paranoia about the Indian Ocean is therefore understandable but the threat according to its strategic commentators comes only from the U.S. Sixty thousand crore [around $10bn] spent on strengthening the Indian Navy’s SLOC interdiction capability would have given us a stranglehold on the Chinese routes through the Indian Ocean. The Himalayan border, the entire border, could have been held hostage by our strength in the Indian Ocean with an investment of Rs.60,000 crore.
Menon’s take is a familiar one. But what is interesting is the scale of pushback against this argument. Zorawar Daulet Singh countered in the Hindu:
While conceptually intuitive, the linkage requires equivalence: Beijing must value the integrity of its SLOCs enough to change its calculus on the mountains. Naval blockades are also complicated operations. The time horizon for success to the point that China would find its resource security threatened would be significantly longer than a swift and limited, continental operation whether pursued for punitive reasons or to change the Line of Actual Control. China’s growing, strategic petroleum reserve, though intended to offset market disruptions, will also be an asset in such a scenario. Further, China’s pursuit of new Eurasian lines of communication, both with growing energy linkages with Russia and connectivity through Central Asia, indicate a potential, declining dependence on Indian Ocean SLOCs at least for some strategic resources. Plainly put, a core interest cannot be secured by peripheral, horizontal escalation.
Bharat Karnad made some similar points in the New India Express:
[A]s empirical evidence shows, a maritime strategy can overcome only island nations (such as Japan in World War II) but by itself can at most seriously discomfit, not stifle, major land powers enjoying interior lines of communications [...]
In a “limited war” launched by PLA, sinking a few Chinese warships found east of the Malacca Strait, or sinking or capturing Chinese merchantmen on the high seas is surely not enough recompense for loss of valuable territory in Arunachal Pradesh and elsewhere along the Line of Actual Control (LAC), and from which the Chinese forces are unlikely to withdraw as they did in 1962. So, the status quo ante will not be restored on land as it will be on the seas.
Karnad also doubts that India’s navy “of 50-odd capital ships by 2030” will be enough to impose a complete blockade on China, and raises the important issue that blockades take much longer to achieve their aim than ground operations:
Indeed, the Chinese could well achieve their limited war aims before many Chinese naval ships and merchant marine can be found and sunk, and the Chinese economy impacted. [...] Thirdly, unlike India, China has built up strategic reserves of oil and minerals; these will last longer than the limited war will endure and before India’s maritime counter can have effect.
Nitin Gokhale concurs, adding:
SLOCs are not an exclusive preserve of either India or China and the international community is therefore bound to intervene to keep the passage free to enable trade and commerce to function normally. A selective blockade of China-centric sea traffic is realistically difficult to implement even if on paper the prospect looks alluring.
This debate is interesting for a few reasons.
First, it represents a quieter echo of a U.S. debate over the feasibility of blockading China. Despite growing interaction between the U.S. and Indian navies, and India’s growing interest in broader Asia-focused debates over China, India still views this question firmly in unilateral terms. The scenarios discussed are usually bilateral disputes between China and India, and envision India acting unilaterally in imposing the hypothetical blockade. 
Second, Indian assessments of the country's maritime strength will be important factors in shaping Indian crisis behavior, particularly as the border dispute flares up once more. Whether or not India believes it possesses this degree of naval leverage might affect whether it feels able to escalate a future crisis on the border.
What's particularly important about this round of the debate is that the specific question of distinguishing Chinese shipping from other international shipping is getting some attention – a practical question that usually is ignored in discussions of the Indian Navy's coercive missions, resulting in the ease of a "blockade" being overstated. 
Third, the debate has implications for interservice resource allocation, with the Navy recently losing out to its rival services. In the 2013-2014 defense budget, the Navy's share of total defense spending fell by the most, and the Navy comprises the smallest share of the budget (18 percent – versus 28 percent for the Indian Air Force and 49 percent for the Indian Army).
Moreover, a recent report by India's Comptroller and Auditor General (CAG) found that the Indian Navy only has "61, 44 and 20 percent respectively of the frigates, destroyers and corvettes that it has projected as its minimum requirement." The debate over whether China is more vulnerable on land or sea has a bearing on how India's resources are spent in the future and whether those shortfalls in boat (and especially submarine) numbers are rectified over the longer-term.
Fourth, and finally, the debate over how to respond to China is valuable because, in being sparked by the decision to raise a mountain corps, it has been couched as a trade-off, and therefore brings the question of priorities to the forefront.
Tradeoffs and priorities lie at the heart of strategy, and it is beneficial for India – a country long criticized for a lack of strategic thinking - that it should be forced to think about the question of military modernization as a series of choices across all dimensions of power, including land, sea, and air, rather than a series of decisions to be made in isolation from one another. 
India was able to throw money at the problem in its period of plenty, but it now faces growth rates much lower than those of the 2000s with little prospect of a swift return to the boom days. The debate between navalists, contintentalists, and others is an important bellwether of how India’s military maturation might progress.  
Shashank Joshi is a Research Fellow of the Royal United Services Institute.